Photobehavioral differentiation within and between the sexes of Drosophila pseudoobscura

1975 ◽  
Vol 53 (10) ◽  
pp. 1395-1402 ◽  
Author(s):  
Robert F. Rockwell ◽  
Rudolf Harmsen ◽  
Fred Cooke ◽  
Joseph Grossfield
Keyword(s):  
Sexual Dimorphism ◽  
Drosophila Pseudoobscura ◽  
Isofemale Line ◽  
Isofemale Lines ◽  
Biochemical Traits ◽  
Behavioral Traits ◽  
Ecological Selection ◽  
Males And Females ◽  
Per Se ◽  
High Degree

Photoresponse and changeability of photoresponse were measured separately with males and females of Drosophila pseudoobscura. The measurements indicate no sexual dimorphism in photobehavior, but do show a distinct sexual dimorphism in changeability of photobehavior. Differentiation between isofemale lines of the population was observed from photobehavior and shown to be of equal magnitude in both sexes. However, such isofemale line differentiation in changeability of photobehavior was very low and restricted to females. Previously published work indicating sexual dimorphism in photobehavior may be the result of experimental designs confounding two effects: (1) photobehavior per se, and (2) changeability of photobehavior.This study of photobehavior suggests that two distinct, but not necessarily mutually exclusive, strategies are involved in the development of intrapopulation differentiation: one leading to a high degree of sexual dimorphism, the other leading to intrasexual differentiation. Concerning the former, it is methodologically and conceptually important to separate sexual dimorphism related to sexual selection from that related to ecological selection. This separation may be easier with behavioral traits than with morphological or biochemical traits.

scholarly journals First Case of Dual Size Asymmetry in an Identical Arthropod Organ: Different Asymmetries of the Combative (Sexual) and Cutting (Non-Sexual) Parts of Mandibles in the Horned Stored-Product Beetle Gnatocerus cornutus (Fabricius, 1798)

Insects ◽  
2018 ◽  
Vol 9 (4) ◽  
pp. 151 ◽  
Author(s):  
Tomas Vendl ◽  
Vaclav Stejskal ◽  
Radek Aulicky
Keyword(s):  
Sexual Dimorphism ◽  
Regulatory Mechanisms ◽  
Directional Asymmetry ◽  
Sexually Dimorphic ◽  
First Case ◽  
Males And Females ◽  
Long Life ◽  
High Degree ◽  
Size Asymmetry ◽  
Single Organ

Although it is known that separate insect body structures may be asymmetrical within one species, the different functional asymmetries within a single organ as a result of differential selective regimes have not been described. Based on microscopic measurements and SEM photography, we examined the size, shape and asymmetry of the mandibular structures of males and females of the sexually dimorphic broad-horned flour beetle, Gnatocerus cornutus (Tenebrionidae, Coleoptera). It was found that sexual dimorphism only manifests in certain outgrowth parts (horns) of male mandibles, while the remaining cutting parts of the mandibles hold identical morphologies for both sexes. A more interesting finding—since this is the first published case of dual functionally selected asymmetry in an identical arthropod organ—was that the cutting part of the male mandible exhibited directional asymmetry, whereas the outgrowth horn part of the mandible showed a high degree of symmetry. Moreover, there was no relationship between the size and asymmetry of horns. The results indicate different regulatory mechanisms of sexually selected combative horns and the food-functional, more conservative (constrained by hard food and adult long life) cutting parts of mandibles.

scholarly journals Evolution of Sex-Dependent Gene Expression in Three Recently Diverged Species of Drosophila

Genetics ◽  
2009 ◽  
Vol 183 (3) ◽  
pp. 1175-1185 ◽  
Author(s):  
Zi-Feng Jiang ◽  
Carlos A. Machado
Keyword(s):  
Gene Expression ◽  
Natural Selection ◽  
Sexual Dimorphism ◽  
Sex Bias ◽  
Drosophila Pseudoobscura ◽  
Expression Divergence ◽  
Behavioral Traits ◽  
Mature Adults ◽  
High Level ◽  
Sexually Mature

Sexual dimorphism in morphological, physiological, and behavioral traits is pervasive in animals, as is the observation of strong sexual dimorphism in genomewide patterns of gene expression in the few species where this has been studied. Studies of transcriptome divergence show that most interspecific transcriptional divergence is highly sex dependent, an observation consistent with the action of sex-dependent natural selection during species divergence. However, few transcriptome evolution studies have been conducted between recently diverged species (<1 MY). Here, we present analyses of sex-biased transcriptome divergence in sexually mature adults of three recently diverged species of Drosophila: Drosophila pseudoobscura, D. persimilis, and D. pseudoobscura bogotana. Data were collected using a custom designed Agilent oligonucleotide. Expression was detected in 12,507 genes. About 80% of the expressed genes show sex-biased expression in each species. Across species, 21% of the transcriptome shows switches between nonsex bias and sex bias, and just 0.9% of the transcriptome shows reversals of sex-biased expression. Over 80% of the expression divergence between species is due to changes in one sex only. About 15% of the expression divergence between species is due to changes in the same direction in both sexes and just 2% is due to changes in both sexes but in opposite directions. In agreement with previous studies, we observe a high level of sex-dependent transcriptome divergence and strong demasculinization of the two arms of the X chromosome in all species. However, in contrast to previous studies we find that male-biased genes do not have higher levels of expression divergence than non-sex-biased genes, and sex-biased genes show higher levels of expression divergence in the alternate sex, suggesting that sex-biased genes endure stronger selection when expressed in the alternate sex.

Observation on the breeding biology of Polypedates teraiensis (Dubois, 1987) (Amphibia: Rhacophoridae)

2017 ◽  
Vol 17 (1) ◽  
pp. 25-32
Author(s):  
Jacinta Lalchhanhimi ◽  
Lalremsanga H.T.
Keyword(s):  
Sexual Dimorphism ◽  
Breeding Season ◽  
Sound Production ◽  
Reproductive Function ◽  
Breeding Biology ◽  
Tree Frog ◽  
University Campus ◽  
Morphometric Measurements ◽  
Advertisement Calls ◽  
Males And Females

The breeding biology of tree frog, Polypedates teraiensis was studied during the breeding season at Mizoram University Campus. It was found that sound production by male during the breeding season was primarily a reproductive function and advertisement calls attract females to the breeding areas and announce other males that a given territory is occupied. The aim of this study was to provide the detailed information on the breeding behaviour and the advertisement calls of Polypedates teraiensis. The morphometric measurements of the amplecting pairs (males and females) for sexual dimorphism along with clutch sizes were also studied.

Sexual Dimorphism among the Kathmandu University Students Assessed by Anthropometric Studies

2018 ◽  
Vol 9 (05) ◽  
pp. 20469-20472
Author(s):  
Shakya R ◽  
Bhattacharya SC ◽  
Shrestha R
Keyword(s):  
Young Adults ◽  
Sexual Dimorphism ◽  
Young Adult ◽  
University Students ◽  
Plastic Surgery ◽  
Age Group ◽  
Adult Age ◽  
Clinically Normal ◽  
Crime Detection ◽  
Males And Females

Objectives: To observe the sexual dimorphism among the young adult age group ranging from 18-21 years, of Kathmandu University students by measuring craniofacial circumference and canthal distances. Rationale of the study: These data could be useful for establishing the craniofacial standards and adds an implementation on plastic surgery, crime detection as well as in the industrial field. Method: 300 clinically normal students of Kathmandu University aged between 18-21 years were examined for the study. Fronto-occipital circumference, outer and inner canthal distances were measured. All the parameters were compared between males and females. Result: The cranial circumference as well as the inner and outer canthal distance in males was found to be significantly higher as compared to the females. Conclusion: The results concluded that sexual dimorphism remarkably exists in young adults of Kathmandu University students.

scholarly journals Sexual dimorphism in the long-term stability (10 years) of skeletal Class III treatment

2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Natalia Tejedor ◽  
Conchita Martín ◽  
José Antonio Alarcón ◽  
María Dolores Oteo-Calatayud ◽  
Juan Carlos Palma-Fernández
Keyword(s):  
Sexual Dimorphism ◽  
Class Iii ◽  
Class Iii Malocclusion ◽  
Skeletal Class ◽  
Term Stability ◽  
Long Term Stability ◽  
Fixed Appliances ◽  
Males And Females ◽  
Class Iii Treatment

Abstract Background Class III malocclusion is associated with high sexual dimorphism, especially in individuals older than 13 years of age, with significant differences in growth between males and females during the pubertal and postpubertal stages, and in adulthood. The aim of this research was to examine differences between males and females in long-term stability (10 years) of treatment for skeletal Class III malocclusion. Methods Thirty patients (15 males and 15 females) with skeletal Class III malocclusion, who had been treated with rapid maxillary expansion (RME) combined with face mask protraction followed by fixed appliances, were selected sequentially. Thirty patients (15 males and 15 females) with skeletal Class I and mesofacial patterns treated only with fixed appliances for dental problems served as the control group. Differences between groups and sexes were evaluated using lateral cephalograms taken at the start of treatment (T0), immediately after the end of treatment (T1), and after 10 years (T2). The long-term treatment success rate was calculated. Results Ten years after Class III treatment, overjet and overbite relapse occurred similarly in females (− 0.68 ± 0.7 mm; − 0.38 ± 0.75 mm, respectively) and males (− 1.09 ± 1.47 mm; − 0.64 ± 0.9 mm, respectively); the ANB angle and Wits appraisal became significantly more negative in males (− 1.37 ± 1.06°; − 2.7 ± 2.53 mm) than in females (− 0.18 ± 1.26°; − 0.46 ± 1.94 mm). The success rate was 73.3% in males and 80% in females. Conclusions Significant differences in the long-term stability of Class III treatment outcomes have been found between males and females, with a larger skeletal Class III relapse and lower long-term success rates in males.

scholarly journals Safe sex: male–female coalitions and pre-copulatory mate-guarding in a fiddler crab

2009 ◽  
Vol 6 (2) ◽  
pp. 180-182 ◽  
Author(s):  
Richard N. C. Milner ◽  
Michael D. Jennions ◽  
Patricia R. Y. Backwell
Keyword(s):  
Sexual Dimorphism ◽  
Reproductive Success ◽  
Observational Data ◽  
Fiddler Crab ◽  
Lower Boundary ◽  
Mate Guarding ◽  
Maintenance Costs ◽  
Boundary Maintenance ◽  
Uca Annulipes ◽  
Males And Females

In fiddler crabs both males and females defend territories that are essential for survival. Given pronounced sexual dimorphism in weaponry, how do weaponless females defend their territory from well-armed males? Using observational data and two simple experiments, we test whether male Uca annulipes protect their female neighbours from conspecific intruders. We show that males defend their female neighbours against male but not female intruders. We also show that females sometimes mate with their immediate neighbours. Male defence of female neighbours appears to represent both pre-copulatory mate-guarding and a territorial coalition. Males who ensure that their neighbour remains female could benefit through increased opportunity for future reproductive success and lower boundary maintenance costs.

scholarly journals Müllerian inhibiting substance contributes to sex-linked biases in the brain and behavior

2009 ◽  
Vol 106 (17) ◽  
pp. 7203-7208 ◽  
Author(s):  
Pei-Yu Wang ◽  
Anna Protheroe ◽  
Andrew N. Clarkson ◽  
Floriane Imhoff ◽  
Kyoko Koishi ◽  
...  
Keyword(s):  
Motor Neurons ◽  
Reproductive Tract ◽  
Behavioral Traits ◽  
Spinal Motor Neurons ◽  
Müllerian Inhibiting Substance ◽  
Males And Females ◽  
Brain And Behavior ◽  
And Behavior ◽  
The Brain ◽  
Mullerian Inhibiting Substance

Many behavioral traits and most brain disorders are common to males and females but are more evident in one sex than the other. The control of these subtle sex-linked biases is largely unstudied and has been presumed to mirror that of the highly dimorphic reproductive nuclei. Sexual dimorphism in the reproductive tract is a product of Müllerian inhibiting substance (MIS), as well as the sex steroids. Males with a genetic deficiency in MIS signaling are sexually males, leading to the presumption that MIS is not a neural regulator. We challenge this presumption by reporting that most immature neurons in mice express the MIS-specific receptor (MISRII) and that male Mis−/− and Misrii−/− mice exhibit subtle feminization of their spinal motor neurons and of their exploratory behavior. Consequently, MIS may be a broad regulator of the subtle sex-linked biases in the nervous system.

Sex differences in white adipose tissue expansion: emerging molecular mechanisms

2021 ◽  
Vol 135 (24) ◽  
pp. 2691-2708
Author(s):  
Simon T. Bond ◽  
Anna C. Calkin ◽  
Brian G. Drew
Keyword(s):  
Sex Differences ◽  
Sexual Dimorphism ◽  
Gene Networks ◽  
Large Scale ◽  
Molecular Mechanisms ◽  
Association Studies ◽  
Tissue Expansion ◽  
Economic Systems ◽  
Genomic Association ◽  
Males And Females

Abstract The escalating prevalence of individuals becoming overweight and obese is a rapidly rising global health problem, placing an enormous burden on health and economic systems worldwide. Whilst obesity has well described lifestyle drivers, there is also a significant and poorly understood component that is regulated by genetics. Furthermore, there is clear evidence for sexual dimorphism in obesity, where overall risk, degree, subtype and potential complications arising from obesity all differ between males and females. The molecular mechanisms that dictate these sex differences remain mostly uncharacterised. Many studies have demonstrated that this dimorphism is unable to be solely explained by changes in hormones and their nuclear receptors alone, and instead manifests from coordinated and highly regulated gene networks, both during development and throughout life. As we acquire more knowledge in this area from approaches such as large-scale genomic association studies, the more we appreciate the true complexity and heterogeneity of obesity. Nevertheless, over the past two decades, researchers have made enormous progress in this field, and some consistent and robust mechanisms continue to be established. In this review, we will discuss some of the proposed mechanisms underlying sexual dimorphism in obesity, and discuss some of the key regulators that influence this phenomenon.

INFANTICIDE

PEDIATRICS ◽  
1978 ◽  
Vol 62 (1) ◽  
pp. 90-90
Author(s):  
Martin Harris
Keyword(s):  
Eighteenth Century ◽  
Population Control ◽  
Effective Means ◽  
Adult Males ◽  
American Museum ◽  
Relative Value ◽  
Demographic Survey ◽  
Female Children ◽  
Males And Females ◽  
Per Se

According to a demographic survey of over 600 primitive populations carried out by William T. Divale of the American Museum of Natural History, there is an extraordinary consistent imbalance of boys over girls in the junior and infant age ranks (up to about 15 years old). [Divale says] that many primitive groups follow a practice of overt female infanticide. Female children are suffocated or simply left unattended in the bush. But more often infanticide is covert, and people usually deny that they practice it.... Warfare inverts the relative value of the contribution made by males and females to a group's prospects for survival. By placing a premium upon maximizing the number of combat-ready adult males, warfare obliges primitive societies to limit their nurturance of females. It is this, and not combat per se, that makes warfare an effective means of controlling population growth.... Lacking any safe and effective means of contraception or abortion, primitive peoples must focus their institutionalized means of population control on individuals who are already alive. Children are the logical victims of these efforts—the younger the better—since number one, they can't resist; number two, there is less of a social and material investment in them; and number three, the emotional ties to infants are easier to cut than those between adults. Anyone who finds my reasoning depraved or "uncivilized" should read about eighteenth-century England. Gin-soaked mothers by the tens of thousands regularly dropped their babies into the Thames or wrapped them in the clothing of smallpox victims, left them in trash barrels, rolled over on top of them during drunken stupors, and otherwise contrived to shorten their babies' lives by direct or indirect means.

scholarly journals Morphometric characters and their relationship in estuarine catfish

1970 ◽  
Vol 6 (2) ◽  
pp. 349-353 ◽  
Author(s):  
M Begum ◽  
Abdullah Al-Mamun ◽  
ML Islam ◽  
MJ Alam
Keyword(s):  
Sexual Dimorphism ◽  
Linear Relationship ◽  
Standard Length ◽  
Head Length ◽  
Pectoral Fin ◽  
Morphometric Characters ◽  
Total Length ◽  
Length Standard ◽  
Eye Diameter ◽  
Males And Females

The morphometric observations were made on total length, standard length, pre-caudal length, head length, eye diameter and depth of body at pectoral fin base of estuarine catfish M. gulio. Males and females showed homogeneity in characters. A linear relationship was found between total length and morphometric characters. Regression of length and weight did not deviate significantly from cube law indicating isometric growth. The fish exhibited sexual dimorphism. Keywords: Morphometric characters; Estuarine catfish; Mystus gulio DOI: 10.3329/jbau.v6i2.4833 J. Bangladesh Agril. Univ. 6(2): 349-353, 2008

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