Male Secondary Sexual Characters Research Articles

Description and conservation status of a new species of Australotomurus (Collembola: Entomobryidae: Orchesellinae) from urban Perth remnant bushland.

A new species of the Australian endemic genus Australotomurus Stach, 1947 A. morbidus sp. nov., is described from four urban remnants in Perth. Australotomurus morbidus sp. nov. is the first species in the genus found to possess male secondary sexual characters on antennal segment III as well as I. The males of all other described species in the genus occurring in south-eastern Australia have secondary sexual characters on antennal segments I and II rather than I and III. Typical habitats for Australotomurus species are long undisturbed native grasslands and heathland at low and high elevations. The new species extends the known distribution of the genus ca. 2,000 km west. Australotomurus morbidus sp. nov. is the only species in the genus currently vulnerable to extinction because of its restricted distribution to only four localities, all of which are subject to considerable human disturbance. This species was listed as critically endangered when it was known (but not yet described) from only one locality but was delisted a few years later when three other locations for the species were found. The history and records of A. morbidus sp. nov. suggest that listing species using current Western Australian legislation does not necessarily protect vulnerable species. The new species is described here and new records for some other Australian species of Orchesellinae provided, including the first Australian record of Heteromurus major (Moniez, 1889).

A novel framework for interpretation of data from the fish short-term reproduction assay (FSTRA) for the detection of endocrine-disrupting chemicals.

The fish short-term reproduction assay (FSTRA) is a key component of the US Environmental Protection Agency's Endocrine Disruptor Screening Program (EDSP), which uses a weight-of-evidence analysis based on data from several assays to identify the potential for chemicals to act as agonists or antagonists of the estrogen or androgen receptors (ER and AR), or inhibitors of steroidogenic enzymes. The FSTRA considers a variety of mechanistic and apical responses in 21-d exposures with the fathead minnow (Pimephales promelas), including plasma steroid and vitellogenin (VTG; egg yolk protein) concentrations, secondary sex characteristics, gonad size and histopathology, and egg production. Although the FSTRA initially was described several years ago, recent data generation associated with implementation of the EDSP highlighted the need for more formal guidance regarding evaluation of information from the assay. The authors describe a framework for interpretation of FSTRA data relative to perturbation of endocrine pathways of concern to the EDSP. The framework considers end points individually and as suites of physiologically related responses relative to pathway identification. Sometimes changes in single end points can be highly diagnostic (e.g., induction of VTG in males by ER agonists, production of male secondary sex characteristics in females by AR agonists); in other instances, however, multiple, related end points are needed to reliably assess pathway perturbation (e.g., AR antagonism, steroid synthesis inhibition). In addition to describing an interpretive framework, the authors demonstrate its practical utility using publicly available FSTRA data for a wide range of known and hypothesized endocrine-disrupting chemicals. Environ Toxicol Chem 2014;33:2529-2540. Published 2014 Wiley Periodicals Inc., on behalf of SETAC. This article is a US government work and, as such, is in the public domain in the United States of America.

A new species of Sybistroma Meigen (Diptera: Dolichopodidae) from the Middle East with a key to West-Palaearctic species of the genus.

A new species, Sybistroma occidasiatica sp. nov., from the Middle East is described. It is close to S. inornata (Loew, 1857), but is distinguished by its long arista-like antennal stylus (longer than postpedicel) and short apicoventral epandrial lobe of the hypopygium (much shorter than cercus). The new species is peculiar in comprising two phenotypes, which can be distinguished by the length ratio of 1^st and 2^nd articles of the antennal stylus. The following recombination is also proposed: Sybistroma caudata (Loew, 1859), comb. nov. (transferred from Gymnopternus Loew, 1857). A checklist of the 26 West-Palaearctic species of the genus is compiled, as well as a key based mainly on male secondary sexual characters. The known distribution of Sybistroma Meigen, 1824, is discussed.

Exposure to paper mill effluent at a site in North Central Florida elicits molecular-level changes in gene expression indicative of progesterone and androgen exposure.

Endocrine disrupting compounds (EDCs) are chemicals that negatively impact endocrine system function, with effluent from paper mills one example of this class of chemicals. In Florida, female Eastern mosquitofish (Gambusia holbrooki) have been observed with male secondary sexual characteristics at three paper mill-impacted sites, indicative of EDC exposure, and are still found at one site on the Fenholloway River. The potential impacts that paper mill effluent exposure has on the G. holbrooki endocrine system and the stream ecosystem are unknown. The objective of this study was to use gene expression analysis to determine if exposure to an androgen receptor agonist was occurring and to couple this analysis with in vitro assays to evaluate the presence of androgen and progesterone receptor active chemicals in the Fenholloway River. Focused gene expression analyses of masculinized G. holbrooki from downstream of the Fenholloway River paper mill were indicative of androgen exposure, while genes related to reproduction indicated potential progesterone exposure. Hepatic microarray analysis revealed an increase in the expression of metabolic genes in Fenholloway River fish, with similarities in genes and biological processes compared to G. holbrooki exposed to androgens. Water samples collected downstream of the paper mill and at a reference site indicated that progesterone and androgen receptor active chemicals were present at both sites, which corroborates previous chemical analyses. Results indicate that G. holbrooki downstream of the Fenholloway River paper mill are impacted by a mixture of both androgens and progesterones. This research provides data on the mechanisms of how paper mill effluents in Florida are acting as endocrine disruptors.

Hypoxia turns genotypic female medaka fish into phenotypic males.

Hypoxia caused by eutrophication is amongst the most pressing global problems in aquatic systems. Notably, more than 400 "dead zones" have been identified worldwide, resulting in large scale collapse of fisheries and major changes in the structure and trophodynamics. Recent studies further discovered that hypoxia can also disrupt sex hormone metabolism and alter the sexual differentiation of fish, resulting in male biased F1 generations and therefore posing a threat to the sustainability of natural populations. However, it is not known whether, and if so how, hypoxia can also change the sex ratio in vertebrates that have sex-determining XX/XY chromosomes. Using the Japanese medaka (Oryzias latipes) as a model, we demonstrate, for the first time, that hypoxia can turn genotypic female fish with XX chromosomes into phenotypic males. Over half of the XX females exposed to hypoxia exhibit male secondary sexual characteristics and develop testis instead of ovary. We further revealed that hypoxia can: (a) down-regulate the vasa gene, which controls proliferation of primordial germ cells and gonadal sex differentiation into ovary, and (b) up-regulate the DMY gene which resides at the sex-determining locus of the Y chromosome, and direct testis differentiation. This is the first report that hypoxia can directly act on genes that regulate sex determination and differentiation, thereby turning genotypic females into phenotypic males and leading to a male-dominant F1 population.

Subcutaneous Testosterone: An Effective Delivery Mechanism for Masculinizing Young Transgender Men.

Testosterone is the recommended treatment for transgender youth who desire the development of male secondary sexual characteristics. While intramuscular injection remains the most common means of delivering injectable testosterone, subcutaneous (SC) delivery has been used with clinical success. No data reporting serum levels and feasibility are available. We aimed to determine both if subcutaneous delivery of testosterone resulted in menstrual cessation, and the normal male ranges of serum testosterone in this subpopulation of female-to-male transgender youth. Within an urban hospital-affiliated Adolescent Medicine clinic, thirty-six youth aged 13 to 24 years transitioning from female to male received testosterone cypionate via subcutaneous injections for masculinization. Participants were a subpopulation of those enrolled in a longitudinal, prospective study examining the impact of treatment for transgender youth. A titrated dose of testosterone cypionate (average dose 46.4 mg per week) via subcutaneous injection was delivered over 6 months. The main outcomes included menstrual cessation as well as raised free and total testosterone levels. Eighty-five percent of participants had ceased menstrual bleeding within 6 months after initiating testosterone. The average time to menstrual cessation was 2.9 months. Most participants (91.4%) reached total testosterone levels within the normal male range after 6 months of subcutaneous delivery (49-1138 ng/dL, 521.4 ng/dL total test). Few adverse effects were reported. Subcutaneous delivery of testosterone for masculinization of transgender youth seems to be effective and well tolerated over short treatment times. Additional studies are needed to determine whether long term use of subcutaneous testosterone delivery yield similar results.

Influence of male courtship intensity and male-male competition on paternity distribution in Hermann's tortoise,Testudo hermanni hermanni(Chelonia: Testudinidae)

Honest-advertisement models of sexual selection suggest that condition-dependent male secondary sexual characters could function as reliable signals of male quality, enabling females to discriminate among potential partners, both in the pre- and post-copulatory phases. In this context, many studies have revealed the importance of promiscuous mating systems and female sperm storage in determining the occurrence of such a model of sexual selection. By contrast, few studies have investigated the presence and extent of post-copulatory female choice in chelonian species. The present study aimed to investigate the effect of male size, male–male competition, and courtship intensity on paternity distribution in Testudo hermanni hermanni, combining behavioural and genetic data. We created experimental groups composed of two males of different sizes and three or four randomly selected females. Observations conducted during social interactions between males revealed that a hierarchy, unrelated to male size, was soon established: Alpha males were more aggressive towards competitors and courted females more intensively. Alpha males also achieved a higher mounting success than Beta males. Paternity analysis performed on hatchlings produced from experimental females revealed that male reproductive success was not correlated with male–female size ratio. Finally, despite the higher mounting success of Alpha males, paternity analysis revealed that male reproductive success did not differ between Alpha and Beta males. © 2014 The Linnean Society of London, Biological Journal of the Linnean Society, 2014, 111, 656–667. ADDITIONAL KEYWORDS: assignment – female choice – intrasexual competition – reproductive success – sperm storage.

The effects of sexual selection on life‐history traits: an experimental study on guppies

Sexual selection is often prevented during captive breeding in order to maximize effective population size and retain genetic diversity. However, enforcing monogamy and thereby preventing sexual selection may affect population fitness either negatively by preventing the purging of deleterious mutations or positively by reducing sexual conflicts. To better understand the effect of sexual selection on the fitness of small populations, we compared components of female fitness and the expression of male secondary sexual characters in 19 experimental populations of guppies (Poecilia reticulata) maintained under polygamous or monogamous mating regimes over nine generations. In order to generate treatments that solely differed by their level of sexual selection, the middle-class neighbourhood breeding design was enforced in the monogamous populations, while in the polygamous populations, all females contributed similarly to the next generation with one male and one female offspring. This experimental design allowed potential sexual conflicts to increase in the polygamous populations because selection could not operate on adult-female traits. Clutch size and offspring survival showed a weak decline from generation to generation but did not differ among treatments. Offspring size, however, declined across generations, but more in monogamous than polygamous populations. By generation eight, orange- and black-spot areas were larger in males from the polygamous treatment, but these differences were not statistically significant. Overall, these results suggest that neither sexual conflict nor the purging of deleterious mutation had important effects on the fitness of our experimental populations. However, only few generations of enforced monogamy in a benign environment were sufficient to negatively affect offspring size, a trait potentially crucial for survival in the wild. Sexual selection may therefore, under certain circumstances, be beneficial over enforced monogamy during captive breeding.

Diagram of the pathways of human steroidogenesis

 Progestogens:  Progesterone, which regulates the cyclical changes of the endometrium of the uterus, and the maintenance of pregnancy  Mineralocorticoids:  Aldosterone, which contributes to the regulation of blood pressure  Glucocorticoids:  Cortisol, whose functions include increasing blood sugar and acting as an immunosuppressant  Androgens:  Testosterone, which contributes to the development and maintenance of male secondary sex characteristics  Estrogens:  Estrogen, which contributes to the development and maintenance of female secondary sex characteristics

Description of Mitogoniella mucuri sp. nov. (Opiliones: Gonyleptidae) and considerations on polymorphic traits in the genus and Gonyleptidae.

Mitogoniella mucuri sp. nov. is described for some caves in Minas Gerais, Brazil. This species differs from other Mitogoniella species by large tubercles on the ocularium that have fused bases and free apices (or almost fully fused tubercles with bifurcated apices), and by a large dry-mark between tubercles on the longitudinal groove of area III. Mitogoniella species are hard to recognize: their males lack any armature on leg IV (normally an important diagnostic character among gonyleptid species), and they also present many polymorphisms in coloration (dry-mark), male secondary sex characters, the number of dorsal scutal granules, and the shapes of tubercles on the ocularium. The patterns of these polymorphisms are discussed for the genus and for the family. The present work also presents new occurrences for all the species of the genus, and their biogeography is discussed.

Age-related changes in the steroid-producing cells of rat testis

PURPOSE: Leydig cells are the main source of testicular hormones that control spermatogenesis, the male reproductive tract, and male secondary sexual characteristics. It is now well established that testosterone levels are reduced with ageing suggesting that there must be deficit in the steroidogenic capacity of ageing Leydig cells. In this respect, the present work aims at describing some structural and functional alterations in rat Leydig cells upon ageing. MATERIAL AND METHODS: Light and electron microscopic observations and immunohistochemistry for 3І-hydroxysteroid dehydrogenase (3І-HSD) were used to identify some structural and functional features of the Leydig cells of ageing rats. RESULTS: The routine histological analysis revealed that during aging (21 and 24 month- old rats) the Leydig cells undergo atrophic changes in size rather than reduction in their number and as consequence the interstitium of ageing testes appeared expanded. The immunoexpression of 3І-HSD as a marker of LC steroidogenic activity decreased after 18 months of age and the immunostaining considerably reduced in 24-month-old rats when compared to that in 3-month-old control ones. Ultrastructural study of Leydig cells in ageing rat testes revealed the presence of Leydig cells with intact morphology as well as Leydig cells with different degree of degeneration. An age-related progressive increase in the number of Leydig cells nuclei that exhibit apoptotic changes like chromatin fragmentation and compaction into dense masses leading to nuclear shrinkage was found out. CONCLUSION: The results obtained suggest that effects of ageing on steroidogenesis are mainly due to structural and functional alterations in Leydig cells resulting in a decreased testosterone production. Scripta Scientifica Medica 2013; 45(3): 32-35. Normal 0 false false false EN-US X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Table Normal; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:10.0pt; font-family:Calibri,sans-serif;}

Hiding Behind Gaudy Looks, a New Central American Species ofPhareas(Hesperiidae: Eudaminae)

ABSTRACT. A new species of Phareas is described from Costa Rica and Panama. Phareas burnsi Grishin, sp. nov. differs from its South American sister species, Phareas coelesteWestwood, 1852, by wing patterns, which were quantified and revealed two clusters with a profound hiatus between them; male secondary sexual characters on hindwing; female genitalia, mostly in the depth of distal notch on lamella postvaginalis; and mitochondrial DNA sequences showing about 4.5% divergence in the COI barcode. Unexpectedly large individual variation in the shape of the Phareas male genitalic valvae is illustrated.

Masculinization of Gene Expression Is Associated with Exaggeration of Male Sexual Dimorphism

Gene expression differences between the sexes account for the majority of sexually dimorphic phenotypes, and the study of sex-biased gene expression is important for understanding the genetic basis of complex sexual dimorphisms. However, it has been difficult to test the nature of this relationship due to the fact that sexual dimorphism has traditionally been conceptualized as a dichotomy between males and females, rather than an axis with individuals distributed at intermediate points. The wild turkey (Meleagris gallopavo) exhibits just this sort of continuum, with dominant and subordinate males forming a gradient in male secondary sexual characteristics. This makes it possible for the first time to test the correlation between sex-biased gene expression and sexually dimorphic phenotypes, a relationship crucial to molecular studies of sexual selection and sexual conflict. Here, we show that subordinate male transcriptomes show striking multiple concordances with their relative phenotypic sexual dimorphism. Subordinate males were clearly male rather than intersex, and when compared to dominant males, their transcriptomes were simultaneously demasculinized for male-biased genes and feminized for female-biased genes across the majority of the transcriptome. These results provide the first evidence linking sexually dimorphic transcription and sexually dimorphic phenotypes. More importantly, they indicate that evolutionary changes in sexual dimorphism can be achieved by varying the magnitude of sex-bias in expression across a large proportion of the coding content of a genome.

Metabolic and Reproductive Effects of Relatively Low Concentrations of Beclomethasone Dipropionate, a Synthetic Glucocorticoid, on Fathead Minnows

Pharmaceuticals present in the aquatic environment could adversely affect aquatic organisms. Synthetic glucocorticoids (GC) are used in large quantities as anti-inflammatory drugs and have been reported to be present in river water. In order to assess the impact of environmental concentrations of GCs, an in vivo experiment was conducted with adult fathead minnows. Fish were exposed to 0.1 μg/L, 1 μg/L, or 10 μg/L beclomethasone dipropionate (BCMD) via a flow-through system over a period of 21 days. Similar duplicate tanks served as control, with no chemical added. There was a concentration-related increase in plasma glucose concentration and a decrease in blood lymphocyte count. Induction of male secondary sexual characters and a decreasing trend in plasma vitellogenin (Vtg) concentrations in female fish were observed with increasing exposure concentration of BCMD. Expression profiles of selected genes (phosphoenolpyruvate carboxykinase - PEPCK, glucocorticoid receptor - GR, and Vtg) in liver also demonstrated concentration-related effects at all three tested concentrations. The results suggest that GCs could cause effects in lower micrograms per liter concentrations that could be environmentally relevant for total GCs present in the environment. Therefore, studies to determine the environmental concentrations of GCs and no effect concentrations are needed to assess if GCs pose a risk to the aquatic environment.

A thermogenic secondary sexual character in male sea lamprey

Secondary sexual characters in animals are exaggerated ornaments or weapons for intrasexual competition. Unexpectedly, we found that a male secondary sexual character in sea lamprey (Petromyzon marinus) is a thermogenic adipose tissue that instantly increases its heat production during sexual encounters. This secondary sexual character, developed in front of the anterior dorsal fin of mature males, is a swollen dorsal ridge known as the 'rope' tissue. It contains nerve bundles, multivacuolar adipocytes and interstitial cells packed with small lipid droplets and mitochondria with dense and highly organized cristae. The fatty acid composition of the rope tissue is rich in unsaturated fatty acids. The cytochrome c oxidase activity is high but the ATP concentration is very low in the mitochondria of the rope tissue compared with those of the gill and muscle tissues. The rope tissue temperature immediately rose up to 0.3°C when the male encountered a conspecific. Mature males generated more heat in the rope and muscle tissues when presented with a mature female than when presented with a male (paired t-test, P<0.05). On average, the rope generated 0.027±0.013 W cm(-3) more heat than the muscle in 10 min. Transcriptome analyses revealed that genes involved in fat cell differentiation are upregulated whereas those involved in oxidative-phosphorylation-coupled ATP synthesis are downregulated in the rope tissue compared with the gill and muscle tissues. Sexually mature male sea lamprey possess the only known thermogenic secondary sexual character that shows differential heat generation toward individual conspecifics.

Phylogenetic systematics of Schacontia Dyar with descriptions of eight new species (Lepidoptera,Crambidae).

The Neotropical genus Schacontia Dyar (1914) is reviewed and revised to include eleven species. Schacontia replica Dyar, 1914, syn. n. and Schacontia pfeifferi Amsel, 1956, syn. n. are synonymized with Schacontia chanesalis (Druce, 1899) and eight new species are described: Schacontia umbra,sp. n., Schacontia speciosa,sp. n., Schacontia themis, sp. n., Schacontia rasa, sp. n., Schacontia nyx,sp. n., Schacontia clotho, sp. n., Schacontia lachesis, sp. n., and Schacontia atropos, sp. n. Three species, Schacontia medalba, Schacontia chanesalis, and Schacontia ysticalis, are re-described. An analysis of 64 characters (56 binary, 8 multistate; 5 head, 13 thoracic, 13 abdominal, 25 male genitalic, and 8 female genitalic) scored for all Schacontia and three outgroup species (Eustixia pupula Hübner, 1823, Glaphyria sesquistrialis Hübner, 1823, and Hellula undalis (Fabricius, 1781)) retrieved 8 equally most parsimonious trees (L=102, CI=71, RI=84) of which the strict consensus is: [[[[medalba + umbra] + chanesalis] + speciosa] + [ysticalis + [rasa + themis + [atropos + lachesis + nyx + clotho]]]]. The relevance of male secondary sexual characters to the diagnosis of Schacontia species is discussed.

Cryptic diversity and gene flow among three African agricultural pests: Ceratitis rosa, Ceratitis fasciventris and Ceratitis anonae (Diptera, Tephritidae)

The 'Ceratitis FAR complex' is a species complex of African fruit flies (Diptera, Tephritidae) including the major agricultural pest Ceratitis rosa and the morphologically similar Ceratitis fasciventris and Ceratitis anonae. To resolve their intra- and interspecific genetic relationships and to estimate gene flow within this complex, we surveyed allelic variation at 16 microsatellite loci in 27 African populations of the three morphospecies. Interpopulation genetic distances and individual Bayesian assignments distinguished five genotypic clusters: two involving C. rosa (R1, R2; that may occur in sympatry), two involving C. fasciventris (F1, F2; with parapatric distributions) and one involving C. anonae (A). Intra- and interspecific patterns of genetic differentiation were not hierarchically structured and genetic differentiation between conspecific clusters (F1-F2 and R1-R2) was higher or comparable with differentiation between heterospecific clusters (e.g. F1-A or R2-A). In some cases, gene flow estimates among morphospecies or among heterospecific genotypic clusters were significantly different from zero, showing the lack of reproductive isolation. Genetic differentiation between genotypic clusters was partly supported by morphological differences observed a posteriori in male secondary sexual characters. These results suggest important revisions to current models of ecological niche requirements and invasion risk of the major agricultural pest C. rosa and provide a basis for a taxonomic re-interpretation of the FAR complex.

Do male secondary sexual characters signal ejaculate quality? A meta‐analysis

There are two reasons why researchers are interested in the phenotypic relationship between the expression of male secondary sexual characters (SSCs) and 'ejaculate quality' (defined as sperm/ejaculate traits that are widely assumed to increase female fertility and/or sperm competitiveness). First, if the relationship is positive then females could gain a direct benefit by choosing more attractive males for fertility assurance reasons ('the phenotype-linked fertility' hypothesis). Second, there is much interest in the direction of the correlation between traits favoured by pre-copulatory sexual selection (i.e. affecting mating success) and those favoured by post-copulatory sexual selection (i.e. increasing sperm competitiveness). If the relationship is negative this could lead to the two forms of selection counteracting each other. Theory predicts that the direction of the relationship could be either positive or negative depending on the underlying genetic variance and covariance in each trait, the extent of variation among males in condition (resources available to allocate to reproductive traits), and variation among males in the cost or rate of mating. We conducted a meta-analysis to determine the average relationship between the expression of behavioural and morphological male secondary sexual characters and four assays of ejaculate quality (sperm number, viability, swimming speed and size). Regardless of how the data were partitioned the mean relationship was consistently positive, but always statistically non-significant. The only exception was that secondary sexual character expression was weakly but significantly positively correlated with sperm viability (r = 0.07, P < 0.05). There was no significant difference in the strength or direction of the relationship between behavioural and morphological SSCs, nor among relationships using the four ejaculate quality assays. The implications of our findings are discussed.

Reproductive and health assessment of fathead minnows (Pimephales promelas) inhabiting a pond containing oil sands process-affected water

Previous laboratory based studies have shown that oil sands process-affected waters (OSPWs) containing high concentrations of naphthenic acids (>25mg/l) have adverse effects on the reproductive physiology of fish. The purpose of this study was to assess the reproductive development and health of a wild population of fathead minnows (Pimephales promelas) inhabiting an OSPW pond that has moderate concentrations of naphthenic acids (∼10mg/l). Fathead minnows were collected at various times during the period of 2006 through 2008 from Demonstration Pond (OSPW) located at Syncrude Canada Ltd., and two reference sites, Beaver Creek reservoir and Poplar Creek reservoir, which are all north of Fort McMurray, AB, Canada. Condition factor, gill histopathology, gonadosomatic indices, liver somatic indices, male secondary sexual characteristics, and plasma sex steroids were examined. Depending on the time of year that fathead minnows were collected, there were differences in the condition factor, gonadosomatic indices, liver somatic indices, and secondary sexual characteristics of fathead minnows (in males) from Demonstration Pond when compared to the fathead minnows from the reference sites. In comparison to reference fish, lower concentrations of 11-ketotestosterone were measured in the plasma of male fathead minnows collected from Demonstration Pond in June 2006 and July 2007. Black spot disease and Ligula intestinalis were prevalent in fathead minnows from the reference sites but were not observed in fathead minnows from Demonstration Pond. The opercula of fathead minnows from Demonstration Pond also differed from those of reference fish. An examination of the gills of fathead minnows from Demonstration Pond revealed that were a number of proliferative and degenerative alterations relative to reference fish. Even though the fathead minnow population has been maintained in this OSPW pond since 1993, the results of this study demonstrate that the OSPW continues to affect the reproductive development and health of the fathead minnows compared to fish collected at reference sites.

Steroid Hormone in Ageing

Copyright: © 2013 Gazi R. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Chemically steroids are similar to that of cholesterol and in most instances these hormones are synthesized from cholesterol. These are lipid soluble and consist of three cyclohexyl rings and one cyclopentyl ring combined into a single structure. Steroids are secreted by the adrenal cortex, ovaries, testis, and placenta. Aldosterone, cortisol, estrogen, and testosterone are some common steroids in the body [1]. Too much or too little secretion of steroids leads to de-arrangements in the body [2]. Estrogen promotes growth and development of female reproductive system, female breast and female secondary sexual characteristics, while testosterone promotes development of male reproductive system and male secondary sexual characteristics. Over production of adrenal androgens leads to adreno-genital syndrome among females; masculinizing effects, develops male pattern of body hair, “Hirsutism” (muscular limbs with deep voice, and small breast in females). However, excess secretion of adrenal androgens in males has no apparent effects but abundance of musculinizing effects.