Zoological Science最新文献_第6页

Contribution of Fat-Signaling and Crumbs-Expanded Modules to Exaggerated Growth of Weaponized Mandible in a Stag Beetle and Its Evolutionary Implications. 脂肪信号和碎屑扩展模块对鹿角甲虫武器化下颌骨过度生长的贡献及其进化意义。

IF 1 4区生物学

Zoological Science Pub Date : 2026-02-01 DOI: 10.2108/zs250047

Yasuhiko Chikami, Taisei Ashimori, Yoshio Ito, Itsuki Ohtsu, Kanta Sugiura, Hiroki Gotoh

{"title":"Contribution of Fat-Signaling and Crumbs-Expanded Modules to Exaggerated Growth of Weaponized Mandible in a Stag Beetle and Its Evolutionary Implications.","authors":"Yasuhiko Chikami, Taisei Ashimori, Yoshio Ito, Itsuki Ohtsu, Kanta Sugiura, Hiroki Gotoh","doi":"10.2108/zs250047","DOIUrl":"10.2108/zs250047","url":null,"abstract":"The weapon trait is typically characterized by an exaggerated body part employed in intrasexual competition, such as male-male combat over mating partners. In the last two decades, EvoDevo studies have engaged in understanding the genetic basis and the evolutionary origin of this sexually selected weapon. However, it remains unclear to what extent factors in the molecular mechanism controlling organ growth regulate the sex- and organ-specific exaggeration of the weapon traits. To this end, we investigate the functions of two well-known organ-growth controlling pathways, Fat-signaling and Crumbs-Expanded modules, for weaponized mandible growth in the Japanese common stag beetle, Dorcus rectus. Here, we find that nine genes of these pathways are involved in mandible extension and morphogenesis along the proximodistal (PD) axis. Some of these genes control the morphogenesis of the distal portion of the leg and antenna and leg size as well. These results suggest that the common role of these genes in appendage growth may be recruited to the exaggerated growth of the Dorcus mandible as a functional module. In addition, our morphometrics shows that dachsous and expanded contribute to sex-linked growth of male mandibles, suggesting that these genes adjust mandible size and shape according to sex through integrating sexual information with organ growth mechanisms. Overall, the weaponized nature of the Dorcus mandible might have originated via the co-option of the Fat-signaling and Crumbs-Expanded module-related genes into mandible exaggeration along the PD axis.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 1","pages":"44-60"},"PeriodicalIF":1.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147285251","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Periodic Activity of Gnrh-Expressing Neurons in the Ciona Brain: Insights into the Origin of Neural Crest Derived GnRH Neurons in Vertebrates. 脑内表达GnRH神经元的周期性活动：脊椎动物神经嵴衍生的GnRH神经元的起源。

IF 1 4区生物学

Zoological Science Pub Date : 2026-02-01 DOI: 10.2108/zs250079

Nanako Okawa, Atsushi Kuhara, Takehiro G Kusakabe

{"title":"Periodic Activity of Gnrh-Expressing Neurons in the Ciona Brain: Insights into the Origin of Neural Crest Derived GnRH Neurons in Vertebrates.","authors":"Nanako Okawa, Atsushi Kuhara, Takehiro G Kusakabe","doi":"10.2108/zs250079","DOIUrl":"10.2108/zs250079","url":null,"abstract":"Gonadotropin-releasing hormone (GnRH) is an important neuropeptide that regulates reproductive function in vertebrates. GnRH-secreting neurons (GnRH neurons) are derived from neurogenic placodes and the neural crest during embryonic development. In the larva of the ascidian Ciona intestinalis type A (Ciona robusta), one of the gnrh genes, gnrh2, is expressed in the protoplacodederived sensory neurons as well as the central nervous system including the brain vesicle, the motor ganglion, and the nerve cord. In this study, we identified gnrh2-expressing cells in the motor ganglion and visualized their activity in tailbud embryos using fluorescent Ca2 + indicator protein G-CaMP8. Two distinct types of cholinergic neurons, vsx+ /pitx+ interneurons (MGIN2s) and islet+ motor neurons (MN2s) were shown to express gnrh2 in the motor ganglion. MN2s showed periodic Ca2 + transients. By contrast, intracellular Ca2 + was static in MGIN2s during development. Periodic Ca2 + transients in MN2s were observed at 14 hours post-fertilization and continued during development. Previous studies demonstrated that MN2s originate from the neural plate border and migrate to the motor ganglion during neural tube formation. The unique properties of the MN2 motor neurons in Ciona are reminiscent of GnRH neurons with pacemaker activity in vertebrates in three aspects: first, they show spontaneous oscillatory activity, second, they migrate apart from the original position in the neural tube during development, and third, they originate from the neural plate border. These similarities suggest that the origin of the neural plate border-derived oscillatory GnRH neurons predates the divergence between vertebrates and tunicates.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"43 1","pages":"95-105"},"PeriodicalIF":1.0,"publicationDate":"2026-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"147285345","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Occurrence of 12 Acoela Species in the Seto Inland Sea. 濑户内海12种甲藻的发生。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs240106

Akira Hikosaka, Ayane Nishimoto, Noriyo Takeda, Tomoe Hikosaka-Katayama

引用次数: 0

Intraspecific Variation in Responsiveness to Juvenile Hormone May Underlie Differences in Diapause Strategy Among Daphnia cf. pulex Clones. 水蚤对幼体激素响应性的种内变异可能是水蚤滞育策略差异的基础。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs250019

Natsumi Maruoka, Hitoshi Miyakawa

{"title":"Intraspecific Variation in Responsiveness to Juvenile Hormone May Underlie Differences in Diapause Strategy Among Daphnia cf. pulex Clones.","authors":"Natsumi Maruoka, Hitoshi Miyakawa","doi":"10.2108/zs250019","DOIUrl":"https://doi.org/10.2108/zs250019","url":null,"abstract":"Daphnids survive unsuitable conditions by producing resting eggs. Resting eggs contribute to population persistence and coexistence by enabling temporal dispersal strategies. Two genotypes of asexual Daphnia cf. pulex (JPN1 and JPN2) differ in the frequency with which they produce resting eggs, despite occurring simultaneously in the same lake. To clarify molecular mechanisms underlying differences in diapause frequency, we hypothesized that juvenile hormone (JH) is involved in resting egg production in Daphnia and that variation in resting egg production between genotypes may reflect differences in responsiveness to JH. We exposed these two D. cf. pulex genotypes to JH analogs and methyl farnesoate (MF), which act on the JH receptor. We found that JH analogs and MF exposure increased resting egg production and did not induce male offspring in the JPN2 genotype. However, in the JPN1 genotype, JH exposure induced male offspring, despite slightly increased resting egg production. Our findings suggest that variation in resting egg production between these two genotypes is partly explained by differences in responsiveness to endogenous JH, potentially influencing population coexistence and dynamics. Finally, we determined that the JH-sensitive period which induces resting egg production occurs about two instars before egg holding. This is slightly earlier than the JH-sensitive period for male production.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"42 6","pages":"587-595"},"PeriodicalIF":1.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Morphological and Molecular Analyses of Cladonema cf. Californicum (Hydrozoa: Anthoathecata) from China. 中国加利福尼亚枝线虫的形态和分子分析（水螅目：花甲纲）。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs240009

Xin-Yu Fang, Shen Lin, Xiao-Peng Zhong, Xu-Lin Zhang, Yu-Ting Zhang, Jian-Ming Chen, Kong-Lin Zhou

{"title":"Morphological and Molecular Analyses of Cladonema cf. Californicum (Hydrozoa: Anthoathecata) from China.","authors":"Xin-Yu Fang, Shen Lin, Xiao-Peng Zhong, Xu-Lin Zhang, Yu-Ting Zhang, Jian-Ming Chen, Kong-Lin Zhou","doi":"10.2108/zs240009","DOIUrl":"https://doi.org/10.2108/zs240009","url":null,"abstract":"In this study, hydrozoan medusae collected from a home aquarium in Sanming, China, were tentatively identified as Cladonema cf. californicum Hyman, 1947, based on DNA barcoding. Morphologically, these specimens differed from known Cladonema medusae, including C. californicum, by possessing a manubrium with protuberances and tentacles with one to three (typically two) adhesive branches, along with three to six (usually four) stinging branches emerging laterally from the main tentacle shaft. These morphological distinctions were supported by molecular phylogenetic analyses using the mitochondrial 16S rRNA and cytochrome c oxidase subunit I (COI) gene sequences. Nonetheless, COI sequences revealed that C. cf. californicum clustered with juvenile Cladonema californicum medusae from California, USA, with a minimal genetic distance of 0.008, indicating potential conspecificity. Given the morphological similarities among juvenile Cladonema medusae, the Californian specimens may have been misidentified. Further investigations focusing on the polyp stage and geographic distribution are necessary to fully resolve the taxonomic status of these medusae and clarify their relationship with C. californicum.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"42 6","pages":"596-604"},"PeriodicalIF":1.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Condition-Dependent Feather Color Change and Condition-Independent Pheomelanin Loss in the Barn Swallow. 条件依赖性羽毛颜色变化和条件非依赖性现象黑色素损失。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs250036

Masaru Hasegawa, Emi Arai, Shosuke Ito, Kazumasa Wakamatsu

{"title":"Condition-Dependent Feather Color Change and Condition-Independent Pheomelanin Loss in the Barn Swallow.","authors":"Masaru Hasegawa, Emi Arai, Shosuke Ito, Kazumasa Wakamatsu","doi":"10.2108/zs250036","DOIUrl":"https://doi.org/10.2108/zs250036","url":null,"abstract":"Feather coloration changes over time, but the underlying mechanisms remain poorly understood. In this study, using the reddish throat feathers of the barn swallow, Hirundo rustica, a well-known sexually selected trait, we examined whether within-season feather color change reflected the change of the major pigment, pheomelanin. As predicted, the reddish feathers faded over time, as their coloration became significantly less red with increasing intervals from the initial capture date to recapture date. Likewise, the pheomelanin content of these feathers significantly decreased with increasing intervals between captures. Neither feather color change nor pheomelanin content change depended on study year, sex, or initial capture date. However, feather color change, but not pheomelanin content change, depended on body condition at the initial capture. This condition-dependent feather color change, together with the condition-independent pheomelanin loss, indicates that seasonal change of the major pigment is insufficient to explain the observed patterns of feather color change. Future study should pay attention to additional colorants that may impact the signal honesty of animal coloration.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"42 6","pages":"565-570"},"PeriodicalIF":1.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688321","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Lineage-Specific Gene Expansion and Atypical Expression Pattern of Feminizing Gene Transformer in Stag Beetles. 瓢虫雌性化基因转换器的谱系特异性基因扩增及非典型表达模式。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs250011

Itsuki Ohtsu, Hayato Kondo, Yasuhiko Chikami, Hideo Dohra, Hiroki Gotoh

{"title":"Lineage-Specific Gene Expansion and Atypical Expression Pattern of Feminizing Gene Transformer in Stag Beetles.","authors":"Itsuki Ohtsu, Hayato Kondo, Yasuhiko Chikami, Hideo Dohra, Hiroki Gotoh","doi":"10.2108/zs250011","DOIUrl":"https://doi.org/10.2108/zs250011","url":null,"abstract":"The molecular cascade of sex determination in insects exhibits remarkable diversity in its upstream factors while conserving the downstream doublesex (dsx) gene across various taxa. dsx encodes a transcription factor that undergoes sex-specific splicing, playing a central role in sex determination. This sex-specific splicing of dsx is generally regulated by the Transformer (Tra) protein. Functional Tra is exclusively expressed in females, governing the female-specific splicing of dsx and inducing feminization. Although the tra gene is widely conserved across various insect species, with the genome typically containing a single copy of the tra gene, it is lost or duplicated in specific taxa, resulting in lineage-specific variations in numbers. Given the flexibility of the tra gene number and meanwhile the deep conservation of its crucial function in sex determination across most investigated taxa, the tra gene has attracted attention as the key gene for evolutionary change in sex-determining mechanisms. In contrast to this conventional insight, unexpectedly, we discovered that the number of tra genes has expanded through gene duplication in stag beetles (Lucanidae, Coleoptera). In addition, we discovered that the tra gene in several species of stag beetles has the same splicing variant in both sexes. Our findings suggest that the tra gene in the Lucanidae family deviates from the basic pattern observed in other insects regarding copy number and expression profiles. The discovery of tra expansion and expression pattern divergence in the family Lucanidae may provide new insights into the evolutionary diversity of the sex differentiation cascade.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"42 6","pages":"571-580"},"PeriodicalIF":1.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688370","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Successful Maintenance of Chemosynthetic Symbiotic Bacterial Abundance in Hydrothermal Mussels During Long-Term Rearing Experiments Exceeding 1000 Days. 热液贻贝在超过1000天的长期饲养实验中成功维持化学合成共生细菌丰度。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs250041

Tetsuro Ikuta, Makoto Sugimura, Ayu Yuasa, Yuka Amari

{"title":"Successful Maintenance of Chemosynthetic Symbiotic Bacterial Abundance in Hydrothermal Mussels During Long-Term Rearing Experiments Exceeding 1000 Days.","authors":"Tetsuro Ikuta, Makoto Sugimura, Ayu Yuasa, Yuka Amari","doi":"10.2108/zs250041","DOIUrl":"https://doi.org/10.2108/zs250041","url":null,"abstract":"Symbiosis with chemosynthetic bacteria is a biological phenomenon that has enabled animals to adapt to deep-sea environments. The deep-sea vent mussel Bathymodiolus septemdierum harbors sulfur-oxidizing symbionts in its gills, which serve as its main source of nutrients. However, the establishment and maintenance of this symbiosis process remain poorly understood, partly because culturing deep-sea mussels and their symbionts is difficult and experimental studies are rare. In the present study, we aimed to establish a rearing method for B. septemdierum and investigate the effects of sodium sulfide (Na2S) addition and gas concentration control in rearing tanks. Three tanks were prepared: a normal tank (tank N), one with Na2S (tank S), and one with Na2S and control dissolved oxygen (tank SO). Mussels were maintained for more than 1000 days, and host survival, gill histology, and the abundance of symbionts were investigated. In tanks N and S, symbionts were depleted within a short period, whereas in tank SO, gill morphology and symbiont abundance were maintained at levels comparable to those of freshly collected individuals, even after 1000 days. However, the survival rate of the host did not correspond to symbiont maintenance. Phylogenetic analysis revealed that the symbiont RuBisCO exists in Form II, which is generally adapted to low-O2 and high-CO2 environments. These results suggest that the long-term maintenance of B. septemdierum symbionts is possible by adding Na2S and controlling the dissolved gas concentration. Further improvements in rearing methods could contribute to a deeper understanding of host-symbiont interactions in this unique deep-sea organism.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"42 6","pages":"521-531"},"PeriodicalIF":1.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688286","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Black-And-White Disruptive Coloration May be Convergent: A New Species of Melita (Amphipoda: Melitidae) from Japan. 黑白分裂色可能趋同：日本Melita一新种（两栖目：melitae科）。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs250074

Ko Tomikawa, Shigeyuki Yamato, Hiroyuki Ariyama

引用次数: 0

Diversity of the Major Histocompatibility Complex Region in the Japanese Population of the Oriental Stork. 日本东方鹳种群主要组织相容性复合体区域的多样性。

IF 1 4区生物学

Zoological Science Pub Date : 2025-12-01 DOI: 10.2108/zs250031

Yui Murakami, Takuro Atsumi, Kazuaki Naito, Shiro Sagawa, Norihide Yokoi, Hiroaki Iwaisaki, Yukio Taniguchi

{"title":"Diversity of the Major Histocompatibility Complex Region in the Japanese Population of the Oriental Stork.","authors":"Yui Murakami, Takuro Atsumi, Kazuaki Naito, Shiro Sagawa, Norihide Yokoi, Hiroaki Iwaisaki, Yukio Taniguchi","doi":"10.2108/zs250031","DOIUrl":"https://doi.org/10.2108/zs250031","url":null,"abstract":"The Oriental stork Ciconia boyciana is a large endangered migratory bird. Since the extinction of the wild Japanese population, conservation programs including captive-breeding and reintroduction have been conducted. The current Japanese population consisting of captive, released, and wild-born individuals originates from 25 founders provided from Russia and China, and one wild individual migrated from the Eurasian continent. Understanding their genetic diversity is critical for effective population management. The major histocompatibility complex (MHC) plays a central role in the vertebrate immune system. Especially, polymorphisms of MHC-IA and -IIA/IIB genes, which encode antigen-presenting molecules, are remarkable and could represent the genetic diversity of population. We report the diversity of the MHC region in the Japanese population of C. boyciana. Sixty-seven individuals, including 10 founders, were used for the analysis. Genotyping of two MHC-IIB genes (DAB and DBB loci) revealed 15 and nine alleles of exon 2s, respectively. The number of MHC class II haplotypes determined by the combination of two alleles of exon 2s in DAB and DBB was 23. Genotyping of the MHC-IA gene (UAA locus) detected four alleles of exon 3. Analysis of the linkage between MHC class II haplotypes and UAA alleles suggested 28 MHC haplotypes and their frequencies were 0.7-12.7%, indicating that the genetic diversity in the Japanese population of C. boyciana was relatively high compared with that in other endangered avian species such as the Japanese crested ibis Nipponia nippon. These results provide valuable information for the genetic management of C. boyciana conservation programs and future studies on avian MHC evolution.","PeriodicalId":24040,"journal":{"name":"Zoological Science","volume":"42 6","pages":"532-539"},"PeriodicalIF":1.0,"publicationDate":"2025-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145688353","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0