scholarly journals Sexual dimorphism in external morphology of the American bullfrog Rana (Aquarana) catesbeiana and the possibility of sex determination based on tympanic membrane/eye size ratio

2020 ◽  
Vol 82 (8) ◽  
pp. 1160-1164
Author(s):  
Masakazu ASAHARA ◽  
Yumi OBAYASHI ◽  
Ayano SUZUKI ◽  
Akane KAMIGAKI ◽  
Takeshi IKEDA
Keyword(s):  
Sexual Dimorphism ◽  
Sex Determination ◽  
Tympanic Membrane ◽  
Size Ratio ◽  
External Morphology ◽  
American Bullfrog ◽  
Eye Size

scholarly journals Effect of captivity on morphology: negligible changes in external morphology mask significant changes in internal morphology

2018 ◽  
Vol 5 (5) ◽  
pp. 172470 ◽  
Author(s):  
Stephanie K. Courtney Jones ◽  
Adam J. Munn ◽  
Phillip G. Byrne
Keyword(s):  
Sexual Dimorphism ◽  
Captive Breeding ◽  
Morphological Changes ◽  
External Morphology ◽  
Wild Animals ◽  
Internal Morphology ◽  
In Captivity ◽  
Two Generations ◽  
Breeding Programmes ◽  
Source Populations

Captive breeding programmes are increasingly relied upon for threatened species management. Changes in morphology can occur in captivity, often with unknown consequences for reintroductions. Few studies have examined the morphological changes that occur in captive animals compared with wild animals. Further, the effect of multiple generations being maintained in captivity, and the potential effects of captivity on sexual dimorphism remain poorly understood. We compared external and internal morphology of captive and wild animals using house mouse ( Mus musculus ) as a model species. In addition, we looked at morphology across two captive generations, and compared morphology between sexes. We found no statistically significant differences in external morphology, but after one generation in captivity there was evidence for a shift in the internal morphology of captive-reared mice; captive-reared mice (two generations bred) had lighter combined kidney and spleen masses compared with wild-caught mice. Sexual dimorphism was maintained in captivity. Our findings demonstrate that captive breeding can alter internal morphology. Given that these morphological changes may impact organismal functioning and viability following release, further investigation is warranted. If the morphological change is shown to be maladaptive, these changes would have significant implications for captive-source populations that are used for reintroduction, including reduced survivorship.

scholarly journals Gender Determination by Linear Dimension of Permanent Canine: An Odontometric Analysis

2014 ◽  
Vol 2 (1) ◽  
pp. 23-27
Author(s):  
B Sharma ◽  
N Balaji ◽  
MK Sumathi
Keyword(s):  
Sexual Dimorphism ◽  
Sex Determination ◽  
Linear Dimension ◽  
Medical Sciences ◽  
Medical College ◽  
Type Iv ◽  
Racial Background ◽  
Significant Difference ◽  
Natural Change ◽  
The Individual

Background and objectives: Identification, an aspect of forensic anthropology, is the recognition of an individual based on the physical characteristics unique to the individual. Among the four main attributes i.e. gender, age, stature and ethnic or racial background of an individual’s biological identity, sex determination is usually the first step in the human identification process. Teeth can be used as a means of sex determination as teeth are resistant to post-mortem degradation and survive deliberate, accidental or natural change. This study was carried out with an objective to determine the sexual dimorphism of maxillary and mandibular canine by linear tooth diameter for permanent dentition in Moradabad population. Material and Methods: A total number of 40 subjects (20 Males and 20 Females) were included in this study. After obtaining an informed written consent, alginate impression was taken with help of perforated impression trays and study models were prepared with type IV dental stone. Linear (MD, BL, Crown Height) were taken with digital vernier caliper. Results: It was observed that males’ shows more mean linear crown diameter as compared to females. Also, the mesiodistal and buccolingual measurement shows statistically significant difference for all canines, being higher for males than females. Conclusion: The present study has expressed sexual dimorphism of permanent canine using Student’s test and indicate that linear dimension of maxillary canine can be used for sexual diamorphism with accuracy along with other accepted procedure for sex determination. DOI: http://dx.doi.org/10.3126/jmcjms.v2i1.11392   Janaki Medical College Journal of Medical Sciences (2014) Vol. 2 (1): 23-27

scholarly journals Auditory brainstem responses in the red-eared slider Trachemys scripta elegans (Testudoformes: Emydidae) reveal sexually dimorphic hearing sensitivity

2019 ◽  
Vol 205 (6) ◽  
pp. 847-854 ◽  
Author(s):  
Tongliang Wang ◽  
Handong Li ◽  
Jianguo Cui ◽  
Xiaofei Zhai ◽  
Haitao Shi ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Tympanic Membrane ◽  
Auditory Brainstem ◽  
Trachemys Scripta ◽  
Auditory Brainstem Responses ◽  
Sexually Dimorphic ◽  
Trachemys Scripta Elegans ◽  
Hearing Sensitivity ◽  
Brainstem Response ◽  
Auditory Systems

Abstract Hearing sensitivity is of general interest from the perspective of understanding the functionality and evolution of vertebrate auditory systems. Sexual dimorphism of auditory systems has been reported in several species of vertebrates, but little is known about this phenomenon in turtles. Some morphological characteristics, such as middle ear and tympanic membrane that influence the hearing sensitivity of animals can result in hearing sexual dimorphism. To examine whether sexual dimorphism in hearing sensitivity occurs in turtles and to compare hearing characteristics with respect to the shape of the tympanic membrane, we measured the hearing sensitivity and tympanum diameter in both sexes of Trachemys scripta elegans. The results showed that, with the exception of 0.9 kHz, auditory brainstem response thresholds were significantly lower in females than in males for frequencies in the 0.2–1.1 kHz range, indicating that the hearing of females shows greater sensitivity. No significant differences were detected in the tympanum diameter of both sexes. These results showed that sexually dimorphic hearing sensitivity has evolved in turtles; however, this difference does not appear to be related to differences in the size of the tympanic membrane. The possible origin and function of the sexual differences in auditory characteristic are discussed.

Morphological characteristics for sexing living adults of Chaetoptelius vestitus (Coleoptera, Curculionidae)

2019 ◽  
Vol 69 (2) ◽  
pp. 173-181
Author(s):  
Ibtihel Ghrissi ◽  
Mohamed Braham ◽  
Imen Said ◽  
James R. LaBonte ◽  
Thomas Shahan
Keyword(s):  
Sex Determination ◽  
Bark Beetle ◽  
Morphological Characteristics ◽  
External Morphology ◽  
Specific Character ◽  
Morphological Criteria ◽  
Non Destructive ◽  
Gender Specific ◽  
Pistachio Trees

Abstract The pistachio bark beetle, Chaetoptelius vestitus (Mulsant & Rey, 1861) is a serious pest of pistachio trees. Despite its phytosanitary importance, some aspects of its biology are still unclear. For example, determining the sex of this beetle is usually complicated by the lack of a discrete, externally visible gender-specific character. Here, the morphological characteristics of C. vestitus were studied in order to detect discriminative features for sexing living beetles. The shape of the seventh visible tergite effectively enabled the separation of the sexes. This method can be quickly learned, is non-destructive and permits sex determination of living C. vestitus adults with 100% accuracy and without damaging the insects. Sex determination using external morphology was confirmed by dissection under a stereomicroscope and by rearing experiments. These morphological criteria were further successfully verified on insects collected on seven other sites in Tunisia.

Sex determination in ostrich (Struthio camelus) using DNA markers

2010 ◽  
Vol 90 (3) ◽  
pp. 357-360 ◽  
Author(s):  
M. Alipanah ◽  
A. Torkamanzehi ◽  
H. Taghavi
Keyword(s):  
Polymerase Chain Reaction ◽  
Sexual Dimorphism ◽  
Sex Determination ◽  
Sex Chromosome ◽  
Molecular Genetic ◽  
Bird Species ◽  
Rapid Identification ◽  
Chain Reaction ◽  
Struthio Camelus ◽  
Polymerase Chain

Production of bird species such as ostrich (Struthio camelus) has been gaining increasing importance in Iran as well as many other countries. Ostrich, similar to many other species of birds, lacks sexual dimorphism, making it difficult to differentiate between males and females, especially at an early age, which can be problematic in breeding programs. Recently developed molecular genetic methods that utilize polymerase chain reaction (PCR) based techniques can facilitate rapid identification of the bird’s sex in these species using a DNA sample, which can be easily extracted from blood or feather pulps. We successfully applied a PCR-based RFLP technique and sex chromosome primers for sex determination in a sample of 30 Ostrich chicks using DNA extracted from blood and feather pulps. Both DNA samples (blood and feather pulps) provided useful results. However, using feather pulps from 1-day-old chicks can provide an easy and inexpensive method for sex determination in ostrich. Key words: Ostrich (struthio camelus), sex determination, sexual dimorphism, polymerase chain reaction, RFLP

scholarly journals Transvection regulates the sex-biased expression of a fly X-linked gene

Science ◽  
2021 ◽  
Vol 371 (6527) ◽  
pp. 396-400 ◽  
Author(s):  
Charalampos Chrysovalantis Galouzis ◽  
Benjamin Prud’homme
Keyword(s):  
Gene Expression ◽  
Sexual Dimorphism ◽  
Sex Determination ◽  
Expression Pattern ◽  
X Chromosome ◽  
Expression Patterns ◽  
Gene Expression Patterns ◽  
Regulatory Interaction ◽  
Linked Gene ◽  
Homologous Chromosomes

Sexual dimorphism in animals results from sex-biased gene expression patterns. These patterns are controlled by genetic sex determination hierarchies that establish the sex of an individual. Here we show that the male-biased wing expression pattern of the Drosophila biarmipes gene yellow, located on the X chromosome, is independent of the fly sex determination hierarchy. Instead, we find that a regulatory interaction between yellow alleles on homologous chromosomes (a process known as transvection) silences the activity of a yellow enhancer functioning in the wing. Therefore, this enhancer can be active in males (XY) but not in females (XX). This transvection-dependent enhancer silencing requires the yellow intron and the chromatin architecture protein Mod(mdg4). Our results suggest that transvection can contribute more generally to the sex-biased expression of X-linked genes.

scholarly journals METHODS FOR DIAGNOSING THE SEX OF ADULT HUMAN BY ANATOMICAL AND MORPHOLOGICAL FEATURES OF ARYTENOID CARTILAGES

2021 ◽  
Author(s):  
Rafkat R Kalimullin ◽  
Viktor N Zvyagin
Keyword(s):  
Sexual Dimorphism ◽  
Sex Determination ◽  
Medical Literature ◽  
Morphological Features ◽  
Sexually Dimorphic ◽  
Arytenoid Cartilage ◽  
Visual Examination ◽  
Chi Square ◽  
Chi Square Test ◽  
The Individual

ABSTRACT. Background. One of the main issues of general personality identification is the ascertainment of the sex of impersonated or fragmented bodies. There are sporadic reports of the larynx cartilage sexual dimorphism in the forensic medical literature, among which arytenoid cartilages are absent. The publications have morphometric focus, the practical aspects of gender diagnostics are not considered, which occasion determined the purpose of this work.Aim: To develop a method for determining sex using sexually dimorphic anatomical and morphological arytenoid cartilage features of an adult. Materials and methods. The anatomical and morphological features of arytenoid cartilage from 160 males (80) and females (80) at the age from 20 to 78 years were studied. The visual examination revealed differences related to gender in 9 characteristics. The reliability of traits' sexual dimorphism was verified using the Chi-square test and proportionality coefficients.Results. The informational significance of the features was clarified and the individual observations were digitized using the formula. The possibility of sex determination by arytenoid cartilage was established in 93.75% of cases. In the remaining 6.25%, there was substantiated the conclusion that it is impossible to solve this problem using a given set of features.Conclusion. The developed method for determining gender is highly accurate and can be used in gender diagnostics in the process of a forensic medical larynx examination of a decayed or a fragmented corpse.

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