Reproductive failure of the red shiner (Cyprinella lutrensis) after exposure to an exogenous estrogen

2010 ◽  
Vol 67 (11) ◽  
pp. 1730-1743 ◽  
Author(s):  
Michelle M. McGree ◽  
Dana L. Winkelman ◽  
Nicole  K.M.  Vieira ◽  
Alan  M.  Vajda
Keyword(s):  
Reproductive Success ◽  
Great Plains ◽  
Endocrine Disrupting Chemicals ◽  
Water Control ◽  
Secondary Sexual Characteristics ◽  
Cyprinella Lutrensis ◽  
The Us ◽  
Sexual Characteristics ◽  
Solvent Control ◽  
17Β Estradiol

Endocrine disrupting chemicals (EDCs) have been detected in surface waters worldwide and can lead to developmental and reproductive disruption in exposed fishes. In the US Great Plains, EDCs are impacting streams and rivers and may be causing adverse reproductive effects. To examine how estrogenic EDCs might affect reproductive success of plains fishes, we experimentally exposed male red shiners ( Cyprinella lutrensis ) to exogenous 17β-estradiol. We characterized the effects of estradiol on male gonadal histology and secondary sexual characteristics, determined whether exposure reduced reproductive success, and examined the effects of depuration. Adults were exposed to a mean concentration of 70 ng·L−1 estradiol, a solvent control, or a water control for at least 83 days. Male exposure to estradiol resulted in elevated plasma vitellogenin concentrations, changes in spermatogenesis, reduced mating coloration and tubercles, altered mating behaviors, and reduced reproductive success with no viable progeny produced. Reproductive endpoints improved upon depuration (28 days). Exposure to estradiol had significant adverse effects on red shiners, indicating that wild populations may face developmental and reproductive difficulties if they are chronically exposed to estradiol.

scholarly journals Endocrine-Disrupting Chemicals and Their Effects during Female Puberty: A Review of Current Evidence

2020 ◽  
Vol 21 (6) ◽  
pp. 2078 ◽  
Author(s):  
Laura Lucaccioni ◽  
Viola Trevisani ◽  
Lucia Marrozzini ◽  
Natascia Bertoncelli ◽  
Barbara Predieri ◽  
...  
Keyword(s):  
Endocrine Disrupting Chemicals ◽  
Current Evidence ◽  
Secondary Sexual Characteristics ◽  
Endocrine Disrupting ◽  
Sexual Characteristics ◽  
Single Chemical ◽  
Windows Of Susceptibility ◽  
Physical Changes ◽  
Temporal Windows

Puberty is the process of physical changes between childhood and adulthood during which adolescents reach sexual maturity and become capable of reproduction. It is considered one of the main temporal windows of susceptibility for the influence of the endocrine-disrupting chemicals (EDCs). EDCs may act as single chemical agents or as chemical mixtures; they can be pubertal influencers, accelerating and anticipating the processing of maturation of secondary sexual characteristics. Moreover, recent studies have started to point out how exposure to EDCs during puberty may predispose to breast cancer later in life. In fact, the estrogen-mimicking endocrine disruptors (EEDs) may influence breast tissue development during puberty in two main ways: the first is the action on the proliferation of the breast stromal cells, the second concerns epigenetic mechanisms. The aim of this mini-review was to better highlight what is new and what is not completely known regarding the role of EDCs during puberty.

Hypogonadism and Testosterone Replacement Therapy

2005 ◽  
Vol 00 (01) ◽  
pp. 75
Author(s):  
Adrian S Dobs
Keyword(s):  
Bone Mass ◽  
Sexual Function ◽  
Replacement Therapy ◽  
External Genitalia ◽  
Testosterone Replacement Therapy ◽  
Male Hypogonadism ◽  
Secondary Sexual Characteristics ◽  
The Us ◽  
Sexual Characteristics ◽  
Normal Spermatogenesis

Male hypogonadism affects an estimated four to five million men in the US. It is defined as failure of the testes to produce an adequate amount of testosterone and/or conduct normal spermatogenesis. The production of adequate amounts of testosterone is necessary for development of external genitalia and development of secondary sexual characteristics in children and adolescents. In adults, androgen production is necessary for maintenance of lean body mass (LBM), bone mass, libido, sexual function, and spermatogenesis.

Pubertal assessment: a national survey of attitudes, knowledge and practices of the US pediatric trainees

2017 ◽  
Vol 30 (6) ◽  
Author(s):  
Aditi Khokhar ◽  
Yagnaram Ravichandran ◽  
Dimitre G. Stefanov ◽  
Sheila Perez-Colon
Keyword(s):  
Online Survey ◽  
Comfort Level ◽  
Clinical Practices ◽  
Continuity Clinic ◽  
Pediatric Residents ◽  
Secondary Sexual Characteristics ◽  
The Us ◽  
Sexual Characteristics ◽  
Recommended Guidelines ◽  
Different Levels

AbstractBackground and objectiveSex maturity rating (SMR), defines different levels of sexual maturity, based on the development of secondary sexual characteristics. Periodic assessment of pubertal maturation by physicians is crucial for timely identification of puberty-related disorders. With this pilot study, we aimed to assess the attitudes, knowledge and practices of pubertal assessment by current US pediatric trainees.MethodsAn anonymous online survey questionnaire was sent to categorical pediatric residents at different levels of training and pediatric chief residents across the US.ResultsWe received responses from 2496 pediatric residents from all over the US. We found that 96% of trainees understand the importance of assessing SMR, 62% feel confident in assessing it and 55% feel comfortable assessing the need for an endocrinology referral. Only 33% of trainees performed external genital exams during all regular clinic visits while 26.9% never performed them during sick visits and 6% never assessed SMR during any of the patient visits. Higher levels of training and having completed an endocrinology rotation were associated with improvement in comfort level, practice and knowledge of trainees regarding pubertal assessment.ConclusionThis study revealed that the current clinical practices of performing external genital exams and SMR among pediatric residents need improvement. Stronger reinforcement from continuity clinic preceptors and/or online and clinic based resources for SMR assessment for trainees may improve adherence to the recommended guidelines.

Sex determination and Y chromosome constitutive heterochromatin

2019 ◽  
Vol 1 (1) ◽  
pp. 1-5
Author(s):  
Abyt Ibraimov
Keyword(s):  
Sex Determination ◽  
Y Chromosome ◽  
Constitutive Heterochromatin ◽  
Sex Differentiation ◽  
Secondary Sexual Characteristics ◽  
Biological Meaning ◽  
Heterochromatin Block ◽  
Sexual Characteristics ◽  
Open Question ◽  
Efficient Elimination

In many animals, including us, the genetic sex is determined at fertilization by sex chromosomes. Seemingly, the sex determination (SD) in human and animals is determined by the amount of constitutive heterochromatin on Y chromosome via cell thermoregulation. It is assumed the medulla and cortex tissue cells in the undifferentiated embryonic gonads (UEG) differ in vulnerability to the increase of the intracellular temperature. If the amount of the Y chromosome constitutive heterochromatin is enough for efficient elimination of heat difference between the nucleus and cytoplasm in rapidly growing UEG cells the medulla tissue survives. Otherwise it doomed to degeneration and a cortex tissue will remain in the UEG. Regardless of whether our assumption is true or not, it remains an open question why on Y chromosome there is a large constitutive heterochromatin block? What is its biological meaning? Does it relate to sex determination, sex differentiation and development of secondary sexual characteristics? If so, what is its mechanism: chemical or physical? There is no scientifically sound answer to these questions.

The Breeding System of the Three-Spined Stickleback, Gasterosteus Aculeatus (Forma Leiura) With Reference To Spatial and Temporal Patterns of Nesting Activity

Behaviour ◽  
1993 ◽  
Vol 126 (1-2) ◽  
pp. 97-124 ◽  
Author(s):  
Sechi Mori
Keyword(s):  
Reproductive Success ◽  
Gasterosteus Aculeatus ◽  
Nest Building ◽  
Lifetime Reproductive Success ◽  
Spatial And Temporal Patterns ◽  
Small Stream ◽  
Nest Distribution ◽  
Nest Sites ◽  
Sexual Characteristics ◽  
Individual Success

Abstract1) The breeding succes of three-spined stickleback (Gasterosteus aculeatus L., forma leiura) males in a small stream of the Tsuya River, Gifu Prefecture, Central Japan, was studied with reference to timing of nesting initiation, use of space for nesting and social interactions. The observations were made almost daily during March to early July 1988 along the shore at a distance of 1-2 m from the fish and nests. 2) All the males in an enclosed study pool were individually marked (99 males). Furthermore, a total of 67 females were marked and observed weekly. The males were individually observed and their agonistic, courtship and parental behaviour as well as their reproductive success were quantified. Reproductive success of individual male was measured as the number of nests built, the number of successful nests, the number of hatched fry per nest. Nest sites were categorized in six types (A-F) on the basis of the proportion of vegetation cover around the nest and distance from the shore. 3) Body size and environmental factors (water temperature, water depth, changes in water level) were not correlated with reproductive success. Flooding was not a major cause of unsuccessful nesting. The brightness of nuptial colouration at the onset of breeding correlated significantly with individual success. Individual variation in the development of secondary sexual characteristics such as a nuptial colouration may have an important consequence for the lifetime reproductive success of the individuals. There was no relationship between fish density and reproductive success. 4) All males that nested more than once had begun breeding early in the season. The sooner a male started nest-building, the more opportunities he had to complete breeding cycles. 5) After an unsuccessful nest, males were significantly more likely to move their nest sites than after a successful nest. The subsequent nesting cycle was not always successful. 6) There was variation in nest-sitc location. The spatial pattern of nest distribution was strongly related to the temporal pattern, because the first males which settled, more often built their nests at sites along the shore where the nest was covered on one or two sides by vegetation. The location of nest site was significantly correlated with reproductive success. When males nested in partly concealed places along the shore, they could sometimes obtain a high reproductive success irrespective of the date of breeding initiation. Thus, reproductive success was largely determined by the timing of nest-building and nest position.

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