Color Variation and Significance of Color in Reproduction in the Damselfly, Argia apicalis (Say) (Zygoptera: Coenagriidae)

1965 ◽  
Vol 97 (1) ◽  
pp. 32-41 ◽  
Author(s):  
George H. Bick ◽  
Juanda C. Bick
Keyword(s):  
Sexual Maturity ◽  
Sex Discrimination ◽  
Single Step ◽  
Color Variation ◽  
Normal Female ◽  
Sex Recognition ◽  
Directional Change ◽  
Males And Females ◽  
Bright Blue

AbstractVariation in thoracic color and the role of color in reproduction were studied in the field in one population of the damselfly, Argia apicalis. Mature males and females were individually marked, and observed near noon on 47 consecutive days, and hourly on three. Males occurred in two color phases: bright blue, and gray-black, neither of which could be positively associated with age or mating. Change was not a single step from blue to finally dark or vice versa but often involved intervening changes in both directions with a maximum of eight in 12 days. Dark was the more temporary condition. Females occurred in three color phases: brown, turquoise, gray-black. As with males, no one phase could be positively associated with age or mating, and multi-directional change occurred after sexual maturity.Dead pinned individuals, modified or not, were presented to living males who: (1) advanced sexually toward motionless models, (2) discriminated intact females from males, (3) reacted sexually more frequently to brown than to the other normal female colors, (4) responded sexually to a female thorax and one wing almost as frequently as to a normal female, (5) accurately discriminated a female thorax and one wing from that of a male. The blue-tipped male abdomen aided but was not indispensable for sex recognition. Dorsal and lateral thoracic color were equally important and elicited male sexual response in their entirety rather than by particular pattern. Sex discrimination broke down when the normal thoracic color was obliterated with paint regardless of its color, but a thorax painted white was an "over-optimal" attraction suggesting the importance of light intensity.

scholarly journals Biological associations of color variation in the Indo-Pacific swimming crab Charybdis hellerii

2015 ◽  
Vol 87 (1) ◽  
pp. 219-232 ◽  
Author(s):  
TIMOTEO T. WATANABE ◽  
FERNANDO J. ZARA ◽  
GUSTAVO Y. HATTORI ◽  
ALEXANDER TURRA ◽  
BRUNO S. SANT'ANNA
Keyword(s):  
Digital Image ◽  
Sexual Maturity ◽  
Physiological State ◽  
Color Pattern ◽  
Color Variation ◽  
Image Editing ◽  
Color Differences ◽  
Commercial Program ◽  
Males And Females ◽  
Female Abdomen

A marine biological invasion is a natural process accelerated by human activities, and the crab Charybdis hellerii is an example of a globally widespread invasive species. This study evaluated color variation in C. hellerii and its relationship to the sex, size and sexual maturity of these crabs, and compared the efficiency of a freeware digital image-editing program with a commercially available program. The color of the individuals was analyzed using standardized digital images. The color pattern varied significantly with size; smaller and immature individuals were darker than larger and mature ones. The female abdomen changed in morphology and color with sexual maturity, becoming wider and orange-colored. There was no statistical difference in the color values between males and females and immature males did not show morphological or color differences in their abdomen. This study highlights the possible relationships of the color and physiological state of the reproductive system, which could help in future studies of behavior, avoiding the need to dissect and/or remove individuals from nature for assessment of sexual maturity. The freeware program showed the same efficiency in digital image analysis as a widely known commercial program.

Gender Diversity in Computing: An Environmental Perspective

10.28945/3248 ◽  
2008 ◽  
Author(s):  
Cecille Marsh
Keyword(s):  
Gender Diversity ◽  
Household Head ◽  
Female Students ◽  
Political Factors ◽  
Female Household Head ◽  
Dominant Female ◽  
Computer Confidence ◽  
Males And Females ◽  
Research Questions

Previous research conducted by the author investigated the socio-political backgrounds of two groups of female students studying computer-related university programmes. They came from distinctly different backgrounds and were enrolled at two institutions with very different legacies. The author found that socio-political factors, in particular the role of a dominant female household head and aggressive governmental affirmative action, had a significant effect on the girls’ levels of confidence and subsequently on their decision to study computer-related courses. Based on this insight, the researcher undertook to look further into gender diversity with respect to self-perceived general computer confidence and self-perceived ability to program a computer. A sample of both female and male Information T echnology students from very similar disadvantaged socio-economic backgrounds was surveyed. The sample of 204 students was drawn from all three years of the National Diploma in Information Technology. The author considered the following research questions: (i) Do males and females studying computer-related courses have differing computer selfefficacy levels? (ii) Do males and females studying computer programming have differing attitudes towards their ability to program? (iii) Do males and females differ in their attitudes towards the programming learning environment?

Selenium Role in Reproduction, Pregnant/Postpartum Women and Neonates: A Current Study

2020 ◽  
Vol 17 (1) ◽  
pp. 28-37
Author(s):  
Tabinda Sattar
Keyword(s):  
Infant Development ◽  
Selenium Deficiency ◽  
Human Reproduction ◽  
Postpartum Women ◽  
Female Reproduction ◽  
Pregnancy And Lactation ◽  
Males And Females ◽  
One Year ◽  
Selenium Supplements

Background: Selenium is a micronutrient, although required in low amounts, its importance in male and female reproduction is well known. Objectives: The core purpose of this study is to evaluate the role of selenium in human reproduction, during pregnancy/ lactation in women and newborns. The review explains side by side the sources of selenium, required amounts of selenium in humans and during pregnancy or lactation. Methods: Selenium deficiency is a major cause of male infertility. Similarly, selenium deficiency, both in pregnant and postpartum women, would greatly affect the health of the newborn baby in all respects. The effect of maternal selenium upon the fetus and the neonates even one year after birth has been explained with some recent examples. Results: The study elaborates the fact that the selenium deficiency in pregnancy and lactation is common due to fetal/infant development, so selenium supplements must be provided in order to overcome these deficiency symptoms. Conclusions: The better reproductive health in humans is possible due to the sufficient amounts of selenium present both in males and females as well.

Sex Discrimination and the Transformation of U.S. Education

2018 ◽  
Author(s):  
Erin E. Buzuvis
Keyword(s):  
Equal Opportunity ◽  
Sex Discrimination ◽  
Sexual Misconduct ◽  
Fourteenth Amendment ◽  
Equal Protection Clause ◽  
Lgbt Students ◽  
Societal Norms ◽  
Sex Equality ◽  
Equality In Education

This chapter highlights the role of Title IX of the Education Amendments Act of 1972 and the U.S. Constitution’s Equal Protection Clause of the Fourteenth Amendment in transforming the gendered landscape of U.S. education. After first providing an overview of these two sources of law, the chapter examines the role they have played in challenging sex-based designations in admissions and in the classroom, in promoting equal opportunity and access to school-sponsored athletics, in challenging sexual harassment and other sexual misconduct, in reducing barriers to LGBT students, and in promoting equal opportunity for students who are pregnant. Sections addressing each one of these topics will also note limitations and shortcomings of the law’s approach to these issues, as there is still more work to do to fully realize sex equality in education. While the law has not cured all the problems of sex discrimination education, owing to limitations in its scope, as well as enforceability, it has proven to be a powerful source of societal norms and expectations, which themselves operate to motivate compliance and beyond.

scholarly journals Genetic Studies of mei-P26 Reveal a Link Between the Processes That Control Germ Cell Proliferation in Both Sexes and Those That Control Meiotic Exchange in Drosophila

Genetics ◽  
2000 ◽  
Vol 155 (4) ◽  
pp. 1757-1772 ◽  
Author(s):  
Scott L Page ◽  
Kim S McKim ◽  
Benjamin Deneen ◽  
Tajia L Van Hook ◽  
R Scott Hawley
Keyword(s):  
Meiotic Recombination ◽  
Double Mutant ◽  
P Element ◽  
Genetic Studies ◽  
Germline Differentiation ◽  
Males And Females ◽  
Bag Of Marbles ◽  
Differentiation And Proliferation

Abstract We present the cloning and characterization of mei-P26, a novel P-element-induced exchange-defective female meiotic mutant in Drosophila melanogaster. Meiotic exchange in females homozygous for mei-P261 is reduced in a polar fashion, such that distal chromosomal regions are the most severely affected. Additional alleles generated by duplication of the P element reveal that mei-P26 is also necessary for germline differentiation in both females and males. To further assess the role of mei-P26 in germline differentiation, we tested double mutant combinations of mei-P26 and bag-of-marbles (bam), a gene necessary for the control of germline differentiation and proliferation in both sexes. A null mutation at the bam locus was found to act as a dominant enhancer of mei-P26 in both males and females. Interestingly, meiotic exchange in mei-P261; bamΔ86/+ females is also severely decreased in comparison to mei-P261 homozygotes, indicating that bam affects the meiotic phenotype as well. These data suggest that the pathways controlling germline differentiation and meiotic exchange are related and that factors involved in the mitotic divisions of the germline may regulate meiotic recombination.

scholarly journals Longitudinal Expression of Testicular TAS1R3 from Prepuberty to Sexual Maturity in Congjiang Xiang Pigs

Animals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 437
Author(s):  
Ting Gong ◽  
Weiyong Wang ◽  
Houqiang Xu ◽  
Yi Yang ◽  
Xiang Chen ◽  
...  
Keyword(s):  
Sexual Maturity ◽  
Cell Function ◽  
Expression Patterns ◽  
Taste Receptor ◽  
Receptor Type ◽  
Mrna Levels ◽  
Early Puberty ◽  
Specific Expression

Testicular expression of taste receptor type 1 subunit 3 (T1R3), a sweet/umami taste receptor, has been implicated in spermatogenesis and steroidogenesis in mice. We explored the role of testicular T1R3 in porcine postnatal development using the Congjiang Xiang pig, a rare Chinese miniature pig breed. Based on testicular weights, morphology, and testosterone levels, four key developmental stages were identified in the pig at postnatal days 15–180 (prepuberty: 30 day; early puberty: 60 day; late puberty: 90 day; sexual maturity: 120 day). During development, testicular T1R3 exhibited stage-dependent and cell-specific expression patterns. In particular, T1R3 levels increased significantly from prepuberty to puberty (p < 0.05), and expression remained high until sexual maturity (p < 0.05), similar to results for phospholipase Cβ2 (PLCβ2). The strong expressions of T1R3/PLCβ2 were observed at the cytoplasm of elongating/elongated spermatids and Leydig cells. In the eight-stage cycle of the seminiferous epithelium in pigs, T1R3/PLCβ2 levels were higher in the spermatogenic epithelium at stages II–VI than at the other stages, and the strong expressions were detected in elongating/elongated spermatids and residual bodies. The message RNA (mRNA) levels of taste receptor type 1 subunit 1 (T1R1) in the testis showed a similar trend to levels of T1R3. These data indicate a possible role of T1R3 in the regulation of spermatid differentiation and Leydig cell function.

Variation within and between Rivers in Adult Size and Sea Age at Maturity of Anadromous Brown Trout, Salmo trutta

1991 ◽  
Vol 48 (6) ◽  
pp. 1015-1021 ◽  
Author(s):  
Jan Henning L'Abée-Lund
Keyword(s):  
Brown Trout ◽  
Sexual Maturity ◽  
Salmo Trutta ◽  
Adult Size ◽  
Age At Maturity ◽  
Migration Distance ◽  
Spawning Area ◽  
Brown Trout Salmo Trutta ◽  
Males And Females ◽  
The Mean

I compared adult size and sea age at sexual maturity among nine populations of anadromous brown trout, Salmo trutta, in two Norwegian rivers to determine the extent of inter- and intrariverine variations. Variation in the mean length of spawners and in the mean sea age at sexual maturity were mainly dependent on the variations found within rather than between rivers. Mean lengths and mean age at maturity of males increased significantly with increasing altitude of the spawning area and with migration distance in freshwater. In females, positive significant correlations were found with mean lengths and altitude of the spawning area and with mean sea age at maturity and both spawning site altitude and migration distance. Mean lengths and ages of males and females were not significantly correlated with the rate of water discharge in the streams during spawning. The size of gravel substrate for spawning was of minor importance in explaining interpopulation variation in mean female size. The increase noted in mean length and in mean sea age at maturity of both males and females is probably an adaptation to greater energy expenditure to reach the uppermost natal spawning areas.

scholarly journals Structural studies on M. tuberculosis O6-methylguanine methyltransferase

2014 ◽  
Vol 70 (a1) ◽  
pp. C832-C832
Author(s):  
Menico Rizzi ◽  
Riccardo Miggiano ◽  
Samarpita Lahiri ◽  
Giuseppe Perugino ◽  
Maria Ciaramella ◽  
...  
Keyword(s):  
Excision Repair ◽  
Single Step ◽  
Double Stranded Dna ◽  
Nucleotide Excision ◽  
Enzymatic Systems ◽  
Methylguanine Methyltransferase ◽  
Mutagenic Effects ◽  
Wild Type Form

Mycobacterium tuberculosis (MTB) is an extremely well adapted human pathogen capable to survive for decades inside the hostile environment represented by the host's infected macrophages despite exposure to multiple potential DNA-damaging stresses. In order to maintain a remarkable low level of genetic diversity, MTB deploys different strategies of DNA repair, including multi-enzymatic systems, such as Nucleotide Excision Repair, and single-step repair. In particular, to counteract the mutagenic effects of DNA alkylation, MTB performs the direct alkylated-base reversal by sacrificing one molecule of a DNA-protein alkyltransferase, such as O6-methylguanine methyltransferase (OGT; orf: Rv1316c). We present here the biochemical and structural characterization of recombinant mycobacterial OGT (MtOGT) in its wild-type form along with its mutated variants mimicking the ones occurring in relevant clinical strains (i.e. MtOGT-T15S and MtOGT-R37L). Our studies reveal that MtOGT-R37L is severely impaired in its activity as consequence of its ten-fold lower affinity for modified double-stranded DNA (dsDNA) (1). Further investigations on a new structure-based panel of OGT versions, designed to explore different molecular environment at position 37, allowed us a better understanding of the functional role of the MtOGT Arg37-bearing loop during catalysis. Moreover, we solved the crystal structure of MtOGT in covalent complex with modified dsDNA that reveals an unprecedented MtOGT::DNA architecture, suggesting that the MtOGT monomer performing the catalysis needs assisting unreacted subunits during cooperative DNA binding. This work is supported by European Community FP7 program SYSTEMTB (Health-F4-2010-241587)

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