著者

Manuel Ruiz-Garcia Esteban Payán Andrea Murillo Diana Alvarez

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.81, no.2, pp.115-127, 2006 (Released:2006-06-06)

参考文献数

51

被引用文献数

20 27

---

The Colombian jaguar population is thought to contain two different subspecies, Panthera onca centralis and Panthera onca onca. The genetic structure of this population was evaluated using 12 microsatellite loci (n = 62 samples). In addition, 22 jaguar DNA samples from Guatemala, Paraguay, Perú, Bolivia, Venezuela and Brazil were analyzed for these microsatellite loci (n = 84 samples). The results of this study indicate six primary themes. First, the levels of gene diversity were very high. Second, the majority of the loci analyzed showed an absence of Hardy-Weinberg equilibrium, probably due to the Wahlund effect (= population subdivision). Third, several microsatellite loci showed significant heterogeneity between the two supposed subspecies in the country. Nevertheless, gene flow was present between them, and heterogeneity was relatively low, although the assignment analyses showed good classification of the jaguars studied into their respective subspecies. Fourth, the long-term historical effective population sizes were calculated through a maximum likelihood procedure for single and multi-step mutation models. Fifth, seven out of twelve DNA microsatellites studied significantly deviated from a single-step mutation model. However, the overall mean multi-step mutation percentage for these 12 DNA microsatellites was only 6%. Therefore, 94% of mutations were uni-step. Sixth, no bottleneck events were detected in the Colombian jaguar population overall.

著者

Maiko Saito Minoru Nakayama Kyota Fujita Atsuko Uchida Hiroyuki Yano Satoshi Goto Hitoshi Okazawa Masaki Sone

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.95, no.6, pp.303-314, 2020-12-01 (Released:2021-03-23)

参考文献数

58

---

yata mutants of Drosophila melanogaster exhibit phenotypes including progressive brain shrinkage, developmental abnormalities and shortened lifespan, whereas in mammals, null mutations of the yata ortholog Scyl1 result in motor neuron degeneration. yata mutation also causes defects in the anterograde intracellular trafficking of a subset of proteins including APPL, which is the Drosophila ortholog of mammalian APP, a causative molecule in Alzheimer’s disease. SCYL1 binds and regulates the function of coat protein complex I (COPI) in secretory vesicles. Here, we reveal a role for the Drosophila YATA protein in the proper localization of COPI. Immunohistochemical analyses performed using confocal microscopy and structured illumination microscopy showed that YATA colocalizes with COPI and GM130, a cis-Golgi marker. Analyses using transgenically expressed YATA with a modified N-terminal sequence revealed that the N-terminal portion of YATA is required for the proper subcellular localization of YATA. Analysis using transgenically expressed YATA proteins in which the C-terminal sequence was modified revealed a function for the C-terminal portion of YATA in the subcellular localization of COPI. Notably, when YATA was mislocalized, it also caused the mislocalization of COPI, indicating that YATA plays a role in directing COPI to the proper subcellular site. Moreover, when both YATA and COPI were mislocalized, the staining pattern of GM130 revealed Golgi with abnormal elongated shapes. Thus, our in vivo data indicate that YATA plays a role in the proper subcellular localization of COPI.

著者

Hinata Kawamura Satoko Hakeda-Suzuki Takashi Suzuki

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.95, no.5, pp.235-247, 2020-10-01 (Released:2021-02-11)

参考文献数

49

被引用文献数

6

---

Neural activity contributes to synaptic regulation in sensory systems, which allows organisms to adjust to changing environments. However, little is known about how synaptic molecular components are regulated to achieve activity-dependent plasticity at central synapses. Previous studies have shown that following prolonged exposure to natural ambient light, the presynaptic active zone (AZ), an area associated with presynaptic neurotransmitter release in Drosophila photoreceptors, undergoes reversible remodeling. Other studies suggest that the secretory protein Wingless (Wg; an ortholog of Wnt-1) can mediate communication between synaptic cells to achieve synaptic remodeling. However, the source of Wg and the mechanism of Wg signal modulation by neuronal activity remained unclear. Here, we found that Wg secreted from glial cells regulates synaptic remodeling in photoreceptors. In addition, antibody staining revealed that Wg changes its localization depending on light conditions. Although Wg is secreted from glial cells, Wg appeared inside photoreceptor axons when flies were kept under light conditions, suggesting that an increase in neuronal activity causes Wg internalization into photoreceptors by endocytosis. Indeed, by blocking endocytosis in photoreceptors, the localization of Wg in photoreceptors disappeared. Interestingly, Wg accumulation was higher in axons with disassembled AZ structure than in axons whose AZ structure was stabilized at the single-cell level, indicating that Wg endocytosis may trigger AZ disassembly. Furthermore, when we genetically activated Wg signaling, Wg accumulation in photoreceptors decreased. Conversely, when we suppressed Wg signaling there was an increase in Wg accumulation. Through RNAi screening of Ca2+-binding proteins in photoreceptors, we found that Calcineurin is a key molecule that triggers Wg endocytosis. Overall, we propose that Wg signaling is regulated by a negative feedback loop driven by Wg endocytosis. The increase in neuronal activity is transmitted via calcium signaling, which leads to a decrease in Wg signaling and thereby promotes presynaptic remodeling.

著者

Aoki Wataru Watanabe Maiko Watanabe Masaki Kobayashi Naoki Terajima Jun Sugita-Konishi Yoshiko Kondo Kazunari Hara-Kudo Yukiko

出版者

日本遺伝学会

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.95, no.3, pp.133-139, 2020

被引用文献数

3

---

<p><i>Entoloma sarcopum</i> is widely known as an edible mushroom but appears morphologically similar to the poisonous mushrooms <i>E. rhodopolium</i> sensu lato (s. l.) and <i>E. sinuatum</i> s. l. Many cases of food poisoning caused by eating these poisonous mushrooms occur each year in Japan. Therefore, they were recently reclassified based on both morphological and molecular characteristics as sensu stricto species. In this study, we analyzed the nucleotide sequences of the rRNA gene (rDNA) cluster region, mainly including the internal transcribed spacer regions and mitochondrial cytochrome oxidase 1 (CO1) gene, in <i>E. sarcopum</i> and its related species, to evaluate performances of these genes as genetic markers for identification and molecular phylogenetic analysis. We found that the CO1 gene contained lineage-specific insertion/deletion sequences, and our CO1 tree yielded phylogenetic information that was not supported by analysis of the rDNA cluster region sequence. Our results suggested that the CO1 gene is a better genetic marker than the rDNA cluster region, which is the most widely used marker for fungal identification and classification, for discrimination between edible and poisonous mushrooms among Japanese <i>E. sarcopum</i> and related species. Our study thus reports a new genetic marker that is useful for detection of Japanese poisonous mushrooms, <i>Entoloma</i>.</p>

著者

Yabin Guan Peng Qu Shugang Lu M. James C. Crabbe Ticao Zhang Yupeng Geng

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.20-00025, (Released:2020-11-11)

参考文献数

61

被引用文献数

4

---

Thlaspi arvense (field pennycress) is widespread in temperate regions of the northern hemisphere. We estimated the genetic and epigenetic structure of eight T. arvense populations (131 individuals) in China using amplified fragment length polymorphism and methylation-sensitive amplified polymorphism molecular-marker techniques. We detected low diversity at both genetic (mean = 0.03; total = 0.07) and epigenetic (mean = 0.04; total = 0.07) levels, while significant genetic (FST = 0.42, P < 0.001) and epigenetic (FST = 0.32, P < 0.001) divergence was found across the distribution range. Using Mantel testing, we found spatial genetic and epigenetic differentiation, consistent with isolation-by-distance models. We also identified a strong correlation between genetic and epigenetic differentiation (r = 0.7438, P < 0.001), suggesting genetic control of the epigenetic variation. Our results indicate that mating system, natural selection and gene flow events jointly structure spatial patterns of genetic and epigenetic variation. Moreover, epigenetic variation may serve as a basis of natural selection and ecological evolution to enable species to adapt to heterogeneous habitats. Our study provides novel clues for the adaptation of T. arvense.

著者

Tomohiro Araki Jiro Osaka Yuya Kato Mai Shimozono Hinata Kawamura Riku Iwanaga Satoko Hakeda-Suzuki Takashi Suzuki

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.19-00066, (Released:2020-06-04)

参考文献数

25

被引用文献数

3

---

In many animals, neural activity contributes to the adaptive refinement of synaptic properties, such as firing frequency and the number of synapses, for learning, memorizing and adapting for survival. However, the molecular mechanisms underlying such activity-dependent synaptic remodeling remain largely unknown. In the synapses of Drosophila melanogaster, the presynaptic active zone (AZ) forms a T-shaped presynaptic density comprising AZ proteins, including Bruchpilot (Brp). In a previous study, we found that the signal from a fusion protein molecular marker consisting of Brp and mCherry becomes diffuse under continuous light over three days (LL), reflecting disassembly of the AZ, while remaining punctate under continuous darkness. To identify the molecular players controlling this synaptic remodeling, we used the fusion protein molecular marker and performed RNAi screening against 208 neuron-related transmembrane genes that are highly expressed in the Drosophila visual system. Second analyses using the STaR (synaptic tagging with recombination) technique, which showed a decrease in synapse number under the LL condition, and subsequent mutant and overexpression analysis confirmed that five genes are involved in the activity-dependent AZ disassembly. This work demonstrates the feasibility of identifying genes involved in activity-dependent synaptic remodeling in Drosophila, and also provides unexpected insight into the molecular mechanisms involved in cholesterol metabolism and biosynthesis of the insect molting hormone ecdysone.

著者

Satoshi Ishishita Yoichi Matsuda

出版者

日本遺伝学会

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.16-00022, (Released:2016-09-15)

被引用文献数

5

---

Hybrid incompatibility is important in speciation as it prevents gene flow between closely related populations. Reduced fitness from hybrid incompatibility may also reinforce prezygotic reproductive isolation between sympatric populations. However, the genetic and developmental basis of hybrid incompatibility in higher vertebrates remains poorly understood. Mammals and birds, both amniotes, have similar developmental processes, but marked differences in development such as the XY/ZW sex determination systems and the presence or absence of genomic imprinting. Here, we review the sterile phenotype of hybrids between the Phodopus dwarf hamsters P. campbelli and P. sungorus, and the inviable phenotype of hybrids between two birds of the family Phasianidae, chicken (Gallus gallus domesticus) and Japanese quail (Coturnix japonica). We propose hypotheses for developmental defects that are associated with these hybrid incompatibilities. In addition, we discuss the genetic and developmental basis for these defects in conjunction with recent findings from mouse and avian models of genetics, reproductive biology and genomics. We suggest that these hybrids are ideal animal models for studying the genetic and developmental basis of hybrid incompatibility in amniotes.

著者

Xin Liu Hua Wang Guang Li Hui-Zhe Huang Yi-Quan Wang

出版者

日本遺伝学会

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.88, no.4, pp.261-269, 2013 (Released:2014-01-25)

参考文献数

25

被引用文献数

2 8

---

Vertebrate Pax1 gene is a member of Pax gene family and encodes a transcription factor associated with crucial roles in the development of pharyngeal pouch, scletrotome and limb bud. In zebrafish, the genome contains two Pax1 paralogs, DrPax1a and DrPax1b, which share high sequence similarity with other Pax1 genes. To elucidate the function of zebrafish DrPax1b gene, we first examined the gene expression pattern and found that it was mainly expressed in the endodermal pharyngeal pouch, caudal somites, notochord, and fin bud. Then, we performed knockdown experiments using antisense morpholino oligonucleotides, which lead to the defects in the vertebral column, tail, pharyngeal skeleton, and pectoral fin. Additionally, we also found that the mouse MmPax1 mRNA, but not the amphioxus AmphiPax1/9 mRNA, could rescue the MO-induced defects. Furthermore, sequence alignment revealed that the N-terminal region of vertebrate Pax1 and amphioxus Pax1/9 were highly conserved, whereas their C-terminal regions were relatively divergent. However, the chimeric Am(N)Dr(C)Pax1, Mm(N)Dr(C)Pax1 and Dr(N)Mm(C)Pax1 mRNA could partially rescue the defects, while the Dr(N)Am(C)Pax1 mRNA could not. In conclusion, our data demonstrate a conserved function of DrPax1b in the development of the vertebral column, pectoral fin and pharyngeal skeleton formation in zebrafish and also provide critical insight into the functional evolution of Pax1 gene by changing its C-terminal sequence.

著者

Kei Fukuda

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.23-00140, (Released:2023-10-20)

参考文献数

159

---

Transposable elements (TEs) are mobile DNA sequences that can insert themselves into various locations within the genome, causing mutations that may provide advantages or disadvantages to individuals and species. The insertion of TEs can result in genetic variation that may affect a wide range of human traits including genetic disorders. Understanding the role of TEs in human biology is crucial for both evolutionary and medical research. This review discusses the involvement of TEs in human traits and disease susceptibility, as well as methods for functional analysis of TEs.

著者

Keiju Kishikawa Kenji Suetsugu Daisuke Kyogoku Kenji Ogaki Daisuke Iga Kohtaroh Shutoh Yuji Isagi Shingo Kaneko

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.94, no.2, pp.95-98, 2019-04-01 (Released:2019-04-27)

参考文献数

16

被引用文献数

5 5

---

We developed microsatellite markers to compare the genetic variation between the putatively cleistogamous Gastrodia takeshimensis (Orchidaceae) and its chasmogamous sister species G. nipponica. We expected low genetic variation in G. takeshimensis in view of its hypothesized cleistogamy. Eighteen primer pairs were developed from a G. takeshimensis genomic DNA library, and their characteristics were tested for G. takeshimensis and G. nipponica. Seven loci were polymorphic in G. nipponica, whereas all loci showed no polymorphism in G. takeshimensis. Genetic diversity was thus not detected in G. takeshimensis, and it seems to have been lost by repeated selfing in the completely closed flower. The 18 markers described here will be useful for investigating the genetic variation between a cleistogamous species and its chasmogamous sister species.

著者

Tomoyuki Furuya Yuki Kondo

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.23-00029, (Released:2023-06-16)

参考文献数

21

---

Members of a plant-specific BES/BZR transcription factor (TF) family including BRI1-EMS-SUPPRESSOR 1 (BES1) and BRASSINAZOLE-RESISTANT 1 (BZR1) regulate various developmental processes and environmental responses. Recently, we reported that BES1/BZR1 Homolog 3 (BEH3) exhibited a competitive effect toward other BES/BZR TFs. In this study, we analyzed transcriptome profiles in BEH3-overexpressing plants and compared them with those of BES1 and BZR1 double gain-of-function mutants. We identified 46 differentially expressed genes (DEGs), which were downregulated in the gain-of-function mutants of BES1 and BZR1 but upregulated upon BEH3 overexpression. In these DEGs, putative BES1 and BZR1 direct-targeted genes were highly enriched. In addition, these DEGs contained not only known brassinosteroid biosynthetic enzymes, but also some NAC TFs, which negatively regulate brassinosteroid-inactivating enzymes. Moreover, the iron sensor and the iron-deficient response-related bHLH TFs were also included. Taken together, our findings indicate that a competitive relationship between BEH3 and other BES/BZR TFs exists in various BES/BZR binding target genes.

著者

Naoki Shitsukawa Chihiro Ikari Sanae Shimada Satoshi Kitagawa Koichi Sakamoto Hiroyuki Saito Hiromichi Ryuto Nobuhisa Fukunishi Tomoko Abe Shigeo Takumi Shuhei Nasuda Koji Murai

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.82, no.2, pp.167-170, 2007 (Released:2007-05-11)

参考文献数

13

被引用文献数

88 96

---

The einkorn wheat (Triticum monococcum) mutant, maintained vegetative phase (mvp), was induced by nitrogen ion-beam treatment and was identified by its inability to transit from the vegetative to reproductive phase. In our previous study, we showed that WAP1 (wheat APETALA1) is a key gene in the regulatory pathway that controls phase transition from vegetative to reproductive growth in common wheat. WAP1 is an ortholog of the VRN1 gene that is responsible for vernalization insensitivity in einkorn wheat. The mvp mutation resulted from deletion of the VRN1 coding and promoter regions, demonstrating that WAP1/VRN1 is an indispensable gene for phase transition in wheat. Expression analysis of flowering-related genes in mvp plants indicated that wheat GIGANTIA (GI), CONSTANS (CO) and SUPRESSOR OF OVEREXPRESSION OF CONSTANS 1 (SOC1) genes either act upstream of or in a different pathway to WAP1/VRN1.

著者

Ryutaro Miyagi Yohey Terai

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.88, no.3, pp.145-153, 2013 (Released:2013-09-11)

参考文献数

76

被引用文献数

11 14

---

The amazing coloration shown by diverse cichlid fish not only fascinates aquarium keepers, but also receives great attention from biologists interested in speciation because of its recently-revealed role in their adaptive radiation in an African lake. We review the important role of coloration in the speciation and adaptive evolution of Lake Victoria cichlids, which have experienced adaptive radiation during a very short evolutionary period. Mature male cichlids display their colors during mate choice. The color of their skin reflects light, and the reflected light forms a color signal that is received by the visual system of females. The adaptive divergence of visual perceptions shapes and diverges colorations, to match the adapted visual perceptions. The divergence of visual perception and coloration indicates that the divergence of color signals causes reproductive isolation between species, and this process leads to speciation. Differences in color signals among coexisting species act to maintain reproductive isolation by preventing hybridization. Thus, the diversity of coloration has caused speciation and has maintained species diversity in Lake Victoria cichlids.

著者

Shasha Wang Yohei Koide Yuji Kishima

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.97, no.4, pp.177-184, 2022-08-01 (Released:2022-12-17)

参考文献数

31

---

The transposon Tam3 of Antirrhinum (snapdragon) has acquired properties that distinguish it from other transposons. Mobile DNA, commonly referred to as a transposable element or transposon, is considered to be synonymous with a selfish factor. That is, a transposable element increases in copy number and moves copies of itself independently of the survival of the host organism. Therefore, the host collectively regulates the transposition activities of most transposable elements in its genome by epigenetic means. However, our analyses of the structure and behavior of Tam3, as shown by the following five results, provide evidence that it does not behave in a selfish manner in relation to the host. 1) Active transposable elements normally increase the abundance of their non-autonomous elements, whereas Tam3 is known to have no non-autonomous elements, and a limited number of around 10 copies of autonomous elements present in the genome have been isolated as active copies. 2) Tam3 does not transpose at 25 ℃, which is the optimal growth temperature for Antirrhinum. Transposition of Tam3 occurs only at low temperatures of about 15 ℃, which is stressful for Antirrhinum. 3) Few strains of Antirrhinum have been found to contain genes that specifically suppress Tam3 transposition. 4) Most of the Tam3 insertions found in Antirrhinum genes do not affect the host genome, and the expression of these host genes is not completely suppressed. 5) Transcription and translation of the Tam3 transposase gene are not epigenetically regulated by the host. These five experimental results constitute evidence that Tam3 retains features that are dissimilar to those of many other transposons and that it does not behave in a selfish manner that is detrimental to the survival of the host. In this review, we consider what kinds of behavior are required if transposons are to establish a mutually beneficial relationship with their hosts, with reference to Tam3.

著者

Hidetaka Ito

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.97, no.4, pp.167, 2022-08-01 (Released:2022-12-17)

著者

Masaki Shirai Takuya Nara Haruko Takahashi Kazuya Takayama Yuan Chen Yudai Hirose Masashi Fujii Akinori Awazu Nobuyoshi Shimoda Yutaka Kikuchi

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.21-00092, (Released:2022-06-18)

参考文献数

42

---

CpG methylation of genomic DNA is a well-known repressive epigenetic marker in eukaryotic transcription, and DNA methylation of promoter regions is correlated with gene silencing. In contrast to the promoter regions, the function of DNA methylation during transcription termination remains to be elucidated. A recent study revealed that mouse DNA methyltransferase 3a (Dnmt3a) mainly functions in de novo methylation in the promoter and gene body regions, including transcription termination sites (TTSs), during development. To investigate the relationship between DNA methylation overlapping the TTSs and transcription termination, we performed bioinformatics analysis using six pre-existing Dnmt-/- mouse cell datasets: four types of neurons (three Dnmt3a-/- and one Dnmt1-/- mutants) and two types of embryonic fibroblasts (MEFs) (Dnmt3a-/- and Dnmt3b-/- mutants). Combined analyses using methylome and transcriptome data revealed that read counts downstream of hypomethylated TTSs were increased in three types of neurons (two Dnmt3a-/- and one Dnmt1-/- mutants). Among these, an increase in chimeric transcripts downstream of the TTSs was observed in Dnmt3a-/- mature olfactory sensory neurons and Dnmt3a-/- agouti-related peptide (protein)-producing neurons, thereby indicating that read-through occurs in hypomethylated TTSs at specific gene loci in these two mutants. Conversely, in Dnmt3a-/- MEFs, we detected reductions in read counts downstream of hypomethylated TTSs. These results indicate that the hypomethylation of TTSs can both positively and negatively regulate transcription termination, dependent on Dnmt and cell types. This study is the first to identify the aberrant termination of transcription at specific gene loci with DNA hypomethylated TTSs attributable to Dnmt deficiency.

著者

Hiroshi Azuma Rhett D. Harrison Keiko Nakamura Zhi-Hui Su

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.85, no.3, pp.177-192, 2010 (Released:2010-10-27)

参考文献数

72

被引用文献数

12 12

---

The interaction between figs (Ficus, Moraceae) and fig-pollinating wasps (Chalcidoidea, Agaonidae) is one of the most specific mutualisms, and thus is a model system for studying coevolution and cospeciation. In this study we focused on figs and their associated fig-wasps found in the Ryukyu and Bonin (Ogasawara) Islands, Japan, because it has been suggested that breakdown in the specificity may occur in islands or at edge of a species’ distribution. We collected 136 samples of 15 native fig species and 95 samples of 13 associated fig-wasps from all major islands in the Ryukyu Islands, including two fig species and one fig-wasp species endemic to the Bonin Islands. We performed molecular phylogenetic analyses using plastid DNA and nuclear ITS sequences for the figs and nuclear 28S rRNA and mitochondrial COI genes for the fig-wasps to investigate the interspecific phylogenies and intraspecific variation within the mutualism. Our phylogenetic analyses using multiple samples per species show the single clade of each fig (except the Bonin endemic species) and fig-pollinating wasp species. Fig species belonging to the same subgenera formed well-supported clades in both plastid and ITS trees, except for the subgenus Urostigma. Likewise, fig wasps emerging from host fig species belonging to the same subgenera formed mostly well supported clades in both 28S and COI trees. Host specificity between the figs and fig-wasps functions strictly in these islands. There was very little sequence variation within species, and that no major geographic structure was found. The two Bonin endemic species (F. boninsimae and F. nishimurae) or their common ancestor and the associated fig-wasps (Blastophaga sp.) are apparently derived from F. erecta and its associated fig-wasps (B. nipponica), respectively, and probably migrated from the Ryukyu Islands.

著者

Michihiko Sugimoto

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.89, no.3, pp.109-120, 2014-06-01 (Released:2014-12-04)

参考文献数

98

被引用文献数

16 24

---

The proximal third of mouse chromosome 17 is known as the t-complex. The t-haplotype is a variant form of this region containing four tandem inversions compared with the wild-type t-complex, and thus recombination in heterozygotes of the t-haplotype is strongly suppressed along the entire t-complex region. Within this genetically locked t-haplotype, many mutations related to various interesting phenotypes (e.g., taillessness, transmission ratio distortion, recessive lethality) have accumulated, and many mouse geneticists have been attracted to t-haplotype research. Many recessive lethal mutations known as t-complex lethal mutations have been found, and detailed phenotypic analyses have revealed that the functions of t-lethal genes are related to important developmental events. Therefore, identification of the genes responsible for these lethal mutations may contribute to our understanding of the mechanisms of mammalian development. In this review, I introduce the phenotypes of t-lethal mutations and describe recent findings, including our results regarding the molecular identification of a t-lethal gene.

著者

Tomoya Suzuki Kanto Nishikawa Yukuto Sato Mamoru Toda

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

pp.21-00046, (Released:2021-11-07)

参考文献数

25

被引用文献数

1

---

Species identification using molecular techniques has recently become common for various taxa. Loop-mediated isothermal amplification (LAMP) is one of the easiest and least expensive molecular identification methods. Although few studies have developed LAMP assays for amphibians, we believe that LAMP is also useful for identifying endangered amphibians. Hynobius tokyoensis and H. lichenatus occur in Honshu, Japan, and have parapatric distributions. They are similar morphologically, especially at early developmental stages, including eggs and larvae. Hynobius tokyoensis has been listed as a national endangered species in Japan since 2020, and unambiguous identification of these species is therefore important for their conservation and management. In this study, we developed a LAMP primer set for the mitochondrial cytochrome b region to detect H. tokyoensis, and we evaluated the LAMP assay using total genomic DNA from four H. tokyoensis and three H. lichenatus individuals from across most of their ranges. Our LAMP primer set could distinguish these two species. This study should help to establish LAMP assays for other endangered species and morphologically similar species.

著者

Yui Hayashi Kanako Takehira Kosuke Nozawa Takamasa Suzuki Yukari Masuta Atsushi Kato Hidetaka Ito

出版者

The Genetics Society of Japan

雑誌

Genes & Genetic Systems (ISSN:13417568)

巻号頁・発行日

vol.95, no.4, pp.183-190, 2020-08-01 (Released:2020-10-23)

参考文献数

46

被引用文献数

3 10

---

Most transposable elements (TEs) are tightly regulated by epigenetic mechanisms such as DNA methylation. RNA-directed DNA methylation (RdDM) is a major control mechanism of TE silencing in plants. We analyzed the transposition activity of a heat-responsive retrotransposon, ONSEN, in Arabidopsis thaliana. Transgenerational transposition was observed in RdDM pathway-deficient mutants upon heat stress. The transposition frequency was higher in the mutants of the upstream processes, but lower in the mutants of the downstream steps, of RdDM. The transposition frequency was not associated with the number of extrachromosomal ONSEN copies. Constitutive heterochromatin of interphase nuclei was dispersed upon heat stress. The degree of decondensation was higher in the RdDM mutants than in wild-type plants subjected to heat stress. We discuss the possible role of RdDM in the regulation of ONSEN transposition upon heat stress.