Sexual determination in zebrafish

2021 ◽  
Vol 79 (1) ◽  
Author(s):  
Devora Aharon ◽  
Florence L. Marlow
Keyword(s):  
2017 ◽  
Vol 10 (1) ◽  
pp. 53 ◽  
Author(s):  
Leandro Luna ◽  
Gustavo Flensborg

<p>El objetivo de este trabajo es evaluar la pertinencia de la métrica dental para obtener información sexual en individuos que habitaron el curso inferior del río Colorado durante el Holoceno tardío (ca. 3000-250 años AP), discutir el grado de dimorfismo sexual e identificar las variables cuantitativas de la dentición que permitan discriminar el sexo de nuevos individuos que se incluyan en futuros análisis. Se estudiaron las medidas máximas bucolinguales y mesiodistales del cuello de los dientes correspondientes a 26 individuos adultos. Las variables más dimórficas corresponden al diámetro bucolingual del canino superior y de ambos segundos molares; en estos casos, las diferencias entre los sexos son estadísticamente significativas. Los resultados obtenidos sobre el dimorfismo sexual se ubican en el extremo superior de los valores correspondientes a diferentes poblaciones humanas. Varios individuos que no contaban con información sexual a través de los métodos tradicionales pudieron ser clasificados desde la métrica dental, lo cual da cuenta del importante potencial de las medidas dentales para contribuir a las caracterizaciones paleodemográficas de conjuntos bioarqueológicos, especialmente en contextos perturbados y con escasa integridad esqueletal.</p><p>Palabras clave: métrica dental; determinación sexual; cazadores-recolectores; curso inferior del río Colorado; Holoceno tardío.</p><p>Abstract<br />The aim of this paper is to evaluate the relevance of dental metrics for obtaining sexual information in individuals who inhabited the lower basin of the Colorado River during the Late Holocene (ca. 3000-250 years BP), to discuss the degree of sexual dimorphism and to identify those quantitative variables adequate for sexual determination of new individuals to be included in future studies. The buccolingual and mesiodistal maximum neck diameters of 26 individual adults were studied. The most dimorphic variables correspond to the buccolingual diameter of the upper canine and both second molars; in these cases, sex differences are statistically significant. The results obtained about sexual dimorphism are located at the upper end of the range for different human populations. Several individuals who had no previous sexual information could be classified using these measurements, which accounts for the significant potential of dental metrics in palaeodemographic characterizations, especially in disturbed bioarchaeological samples.</p><p>Keywords: dental metrics; sexual determination; hunter-gatherers; lower basin of the Colorado River; Late Holocene.</p>


2019 ◽  
Vol 85 ◽  
pp. 102400
Author(s):  
Adriana Martínez-Juárez ◽  
Norma Moreno-Mendoza
Keyword(s):  

Author(s):  
Sven Thatje ◽  
Gustavo A. Lovrich

The decapodid and first two juvenile stages of the caridean shrimp Campylonotus vagans from the Subantarctic Beagle Channel (Tierra del Fuego, Argentina) are described and illustrated in detail. The complete larval and early juvenile development of this species from rearings under controlled laboratory conditions were analysed. Zoeal morphology in two stages of an abbreviated development was identical to a description from plankton and hatched larvae of a previous work, and therefore we only compare and discuss slight morphological variations in this study. The first juvenile is large and already resembles some features of adults, lacking all ventral rostral and the fourth dorsal rostral spine only which appears in the following stage, and the second pereiopod not yet being as predominant as in adults. Sexual determination is not yet possible up to the described second juvenile stage. The abbreviated larval development in a Subantarctic shrimp species is discussed as an adaptation to low temperatures and pronounced seasonality.


2016 ◽  
Vol 266 ◽  
pp. 588.e1-588.e6 ◽  
Author(s):  
Suguru Torimitsu ◽  
Yohsuke Makino ◽  
Hisako Saitoh ◽  
Ayaka Sakuma ◽  
Namiko Ishii ◽  
...  

2019 ◽  
Author(s):  
Ji-Chong Zhuo ◽  
Hou-Hong Zhang ◽  
Yu-Cheng Xie ◽  
Han-Jing Li ◽  
Qing-Ling Hu ◽  
...  

AbstractThe sex determination mechanism for hemipteran species remains poorly understood. During the sex determination of the brown planthopper (BPH), Nilaparvata lugens, one species of Hemiptera, the functions of doublesex (Nldsx) and NlTra-2 (NlTra-2) genes were identified in our previous studies. Here, we identify an upstream gene for Nldsx in the sex determination cascade, NlFmd, which acts as female determinant gene for N. lugens. The sex-specific transcript of NlFmd (NlFmd-F) encodes an arginine/serine-, and proline-rich protein that is essential for female development. The knockdown of NlFmd resulted in the development of pseudomales, with sex-specific alternative Nldsx processing, and maternal RNA interference (RNAi) against NlFmd generates male-only progeny. Moreover, homologous genes for NlFmd have also been identified in two rice planthopper species, the white-backed planthopper (WBPH, Sogotalla furcifera) and the small brown planthopper (SBPH, Laodelphax striatellus), and these genes appear to be involved in the sex determination cascades for these species. Our data suggest that the sex determination cascade in Delphacidae is conserved.


Author(s):  
G. B. Protyusha ◽  
Sivapathasundharam B.

Sex determination is arguably the most defining moment of our lives, the point where we inherit X or Y chromosome from our father. This initiates a cascade of events that sets in a train of morphological changes, genetic regulations and molecular mechanisms. Following this, our fate is further sealed during sex differentiation and gonadal development owing to the action of sex-specific gonadal hormones. Therefore, the profoundly divergent journeys of male and female lives are decided just by the toss of a genetic coin. The existence of a third gender is also an undeniable aspect of our society. The understanding of the functioning and genetic regulation of the complex process of sexual determination and differentiation is pivotal in comprehension of the basis of human life. Any deviation from the usual mechanisms in the critical stages of development leads to disorders of sexual differentiation leading to sexual ambiguity among individuals. This review discusses the mechanisms that contribute to female and male sex determination and gonadal development, in an attempt to understand the basics of human sex.


2019 ◽  
Author(s):  
Pengjie Hu ◽  
Huimin Liu ◽  
Lei Chen ◽  
Guang-Jun He ◽  
Xiuyun Tian ◽  
...  

AbstractIn fungi, the sex-determination program universally directs sexual development and syngamy (the fusion of gametes) that underlies pre-meiotic diploidization. However, the contribution of sex-determination to syngamy-independent sexual cycle, which requires autopolyploidization as an alternative approach to elevate ploidy before meiosis, remains unclear in fungi and other eukaryotes. The human fungal pathogen Cryptococcus neoformans, as a model organism for studying fungal sexual reproduction, can undergo syngamy-dependent bisexual and syngamy-independent solo unisexual reproduction, in which endoreplication is considered to enable pre-meiotic self-diploidization. Here, by characterizing a mutant lacking all the core sex-determination factors, we show that sex-determination plays a central role in bisexual syngamy but is not strictly required for unisexual development and self-diploidization. This implies an unknown circuit, rather than the sex-determination program, for specifically coordinating Cryptococcus unisexual cycle. We reveal that syngamy and self-diploidization are both governed by the Qsp1-directed paracrine system via two regulatory branches, Vea2 and Cqs2. Vea2 directs bisexual syngamy through the sex-determination program; conversely, Cqs2 is dispensable for bisexual syngamy but activates unisexual endoreplication. Through functional profiling of 41 transcription factors documented to regulate Cryptococcus sexual development, we reveal that only Cqs2 can drive and integrate all unisexual phases and ensure the production of meiospore progenies. Furthermore, ChIP-seq analysis together with genetic evaluation indicate that Cqs2 induces unisexual self-diploidization through its direct control of PUM1, whose expression is sufficient to drive autopolyploidization. Therefore, Cqs2 serves as the critical determinant that orchestrates Cryptococcus multistage unisexual cycle that does not strictly require the sexual-determination program.


Sign in / Sign up

Export Citation Format

Share Document