Female human resources development: growth and equity as priorities

Includes bibliography

Neonatally induced mild diabetes: influence on development, behavior and reproductive function of female Wistar rats

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Prenatal exposure to testosterone masculinises the female gerbil and promotes the development of lesions in the prostate (Skene

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Bisphenol-A promotes antiproliferative effects during neonatal prostate development in male and female gerbils

Conselho Nacional de Desenvolvimento Científico e Tecnol[ogico (CNPq)

Initial Development of a Web-Based Tool to Increase Hunter Harvest of Female Ungulates

Landowners and agencies have expressed difficulty finding hunters willing to harvest the female portion of the ungulate populations, and likewise, hunters have expressed difficulty achieving access to private lands. Since 2003, the Montana “DoeCowHunt” website (www.doecowhunt.montana.edu) has provided an avenue to improve hunter-landowner contact and wild ungulate population management. A product of Montana State University Extension Wildlife Program, this website provides a means for hunters and landowners in Montana to contact each other by listing contact information (email address, physical address, and telephone number) for the purpose of harvesting antlerless ungulates. In the first year over 10,000 users visited the site. Of those who actually registered, 11 were landowners and 1334 were hunters. An evaluation survey resulted in a 40% response rate. The survey indicated the average registered landowner had 20 hunter contacts. Many landowners contacted hunters through use of the website but did not register or list their contact information on the site.

Thyroid hormone action is required for normal cone opsin expression during mouse retinal development

PURPOSE. The expression of S- and M-opsins in the murine retina is altered in different transgenic mouse models with mutations in the thyroid hormone receptor (TR)-beta gene, demonstrating an important role of thyroid hormone (TH) in retinal development. METHODS. The spatial expression of S- and M-opsin was compared in congenital hypothyroidism and in two different TR mutant mouse models. One mouse model contains a ligand-binding mutation that abolishes TH binding and results in constitutive binding to nuclear corepressors. The second model contains a mutation that blocks binding of coactivators to the AF-2 domain without affecting TH binding. RESULTS. Hypothyroid newborn mice showed an increase in S- opsin expression that was completely independent of the genotype. Concerning M-opsin expression, hypothyroidism caused a significant decrease (P < 0.01) only in wild-type animals. When TR beta 1 and -beta 2 were T3-binding defective, the pattern of opsin expression was similar to TR beta ablation, showing increased S- opsin expression in the dorsal retina and no expression of M-opsin in the entire retina. In an unexpected finding, immunostaining for both opsins was detected when both subtypes of TR beta were mutated in the helix 12 AF-2 domain. CONCLUSIONS. The results show, for the first time, that the expression of S- and M-opsin is dependent on normal thyroid hormone levels during development.

Neonatally induced mild diabetes: influence on development, behavior and reproductive function of female Wistar rats

Abstract Background Neonatal STZ treatment induces a state of mild hyperglycemia in adult rats that disrupts metabolism and maternal/fetal interactions. The aim of this study was investigate the effect of neonatal STZ treatment on the physical development, behavior, and reproductive function of female Wistar rats from infancy to adulthood. Methods At birth, litters were assigned either to a Control (subcutaneous (s.c.) citrate buffer, n = 10) or STZ group, (streptozotocin (STZ) - 100 mg/kg-sc, n = 6). Blood glucose levels were measured on postnatal days (PND) 35, 84 and 120. In Experiment 1 body weight, length and the appearance of developmental milestones such as eye and vaginal opening were monitored. To assess the relative contribution of the initial and long term effects of STZ treatment this group was subdivided based on blood glucose levels recorded on PND 120: STZ hyperglycemic (between 120 and 300 mg/dl) and STZ normoglycemic (under 120 mg/dl). Behavioral activity was assessed in an open field on PND 21 and 75. In Experiment 2 estrous cyclicity, sexual behavior and circulating gonadotropin, ovarian steroid, and insulin levels were compared between control and STZ-hyperglycemic rats. In all measures the litter was the experimental unit. Parametric data were analyzed using one-way or, where appropriate, two-way ANOVA and significant effects were investigated using Tukey’s post hoc test. Fisher’s exact test was employed when data did not satisfy the assumption of normality e.g. presence of urine and fecal boli on the open field between groups. Statistical significance was set at p < 0.05 for all data. Results As expected neonatal STZ treatment caused hyperglycemia and hypoinsulinemia in adulthood. STZ-treated pups also showed a temporary reduction in growth rate that probably reflected the early loss of circulating insulin. Hyperglycemic rats also exhibited a reduction in locomotor and exploratory behavior in the open field. Mild hyperglycemia did not impair gonadotropin levels or estrous cylicity but ovarian steroid concentrations were altered. Conclusions In female Wistar rats, neonatal STZ treatment impairs growth in infancy and results in mild hyperglycemia/hypoinsulinemia in adulthood that is associated with changes in the response to a novel environment and altered ovarian steroid hormone levels.

Importance of dietary n-3 hufa for eye development and cone formation along gilthead seabream sparus aurata larval development.

[EN] Being fish larvae visual feeders, vision plays an important role in larval orientation at first feeding (Blaxter, 1986). Larval trophic behaviour is closely related with the development of the visual capacity, which directly depends on retina organogenesis. In sparids, such as Pagrus major (Kawamura, 1984) and Pagrus auratus (Pankhurst, 1996), the most important changes in the eye structure occur along the lecitotrophic stage as a preparation for prey capture. Neuringer et al.,(1988) has established a critical role for n-3 polyunsaturated fatty acids and, particularly docosahexaenoic acid (DHA) in neural and retinal tissue functions in mammals. Similarly, in larval fish there is a high demand of DHA to form nervous membranes. Bell and Dick (1993) found photoreceptors in the eye, rods and cones accumulate and selectively retain DHA in external segments.Bell et al. (1995) found that feeding juvenile herring a DHA poor Artemia diet during the period of rod development resulted in impaired vision at low light intensities, when rod vision is essential.

Differential expression of IGF-I mRNA and peptide in the male and female gonad during early development of a bony fish, the tilapia Oreochromis niloticus

Insulin-like growth factor I (IGF-I) plays a key role in the complex system that regulates bony fish growth, differentiation, and reproduction. The major source of circulating IGF-I is liver, but IGF-I-producing cells also occur in other organs, including the gonads. Because no data are available on the potential production sites of IGF-I in gonad development, developmental stages of monosex breedings of male and female tilapia from 0 day postfertilization (DPF) to 90 DPF were investigated for the production sites of IGF-I at the peptide (immunohistochemistry) and mRNA (in situ hybridization) level. IGF-I mRNA first appeared in somatic cells of the male and female gonad anlage at 7 DPF followed by IGF-I peptide around 9-10 DPF. Gonad anlagen were detected from 7 DPF. Starting at 7 DPF, IGF-I peptide but no IGF-I mRNA was observed in male and female primordial germ cells (PGCs) provided that IGF-I mRNA was not under the detection level, this observation may suggest that IGF-I originates from the somatic cells and is transferred to the PGCs or is of maternal origin. While in female germ cells IGF-I mRNA and peptide appeared at 29 DPF, in male germ cells both were detected as late as at 51-53 DPF. It is assumed that the production of IGF-I in the germ cells is linked to the onset of meiosis that in tilapia ovary starts at around 28 DPF and in testes at around 52-53 DPF. In adult testis, IGF-I mRNA and peptide occurred in the majority of spermatogonia and spermatocytes as well as in Leydig cells, the latter indicating a role of IGF-I in the synthesis of male sex steroids. In adult ovary, IGF-I mRNA and IGF-I peptide were always present in small and previtellogenic oocytes but only IGF-I peptide infrequently occurred in oocytes at the later stages. IGF-I expression appeared in numerous granulosa and some theca cells of follicles at the lipid stage and persisted in follicles with mature oocytes. The results suggest a crucial role of local IGF-I in the formation, differentiation and function of tilapia gonads.

Ethinylestradiol differentially interferes with IGF-I in liver and extrahepatic sites during development of male and female bony fish

Growth and sexual development are closely interlinked in fish; however, no reports exist on potential effects of estrogen on the GH/IGF-I-axis in developing fish. We investigate whether estrogen exposure during early development affects growth and the IGF-I system, both at the systemic and tissue level. Tilapia were fed from 10 to 40 days post fertilization (DPF) with 17alpha-ethinylestradiol (EE(2)). At 50, 75, 90, and 165 DPF, length, weight, sex ratio, serum IGF-I (RIA), pituitary GH mRNA and IGF-I, and estrogen receptor alpha (ERalpha) mRNA in liver, gonads, brain, and gills (real-time PCR) were determined and the results correlated to those of in situ hybridization for IGF-I. Developmental exposure to EE(2) had persistent effects on sex ratio and growth. Serum IGF-I, hepatic IGF-I mRNA, and the number of IGF-I mRNA-containing hepatocytes were significantly decreased at 75 DPF, while liver ERalpha mRNA was significantly induced. At 75 DPF, a transient decline of IGF-I mRNA and a largely reduced number of IGF-I mRNA-containing neurons were observed in the female brain. In both sexes, pituitary GH mRNA was significantly suppressed. A transient downregulation of IGF-I mRNA occurred in ovaries (75 DPF) and testes (90 DPF). In agreement, in situ hybridization revealed less IGF-I mRNA signals in granulosa and germ cells. Our results show for the first time that developmental estrogen treatment impairs GH/IGF-I expression in fish, and that the effects persist. These long-lasting effects both seem to be exerted indirectly via inhibition of pituitary GH and directly by suppression of local IGF-I in organ-specific cells.

Dicer is required for female reproductive tract development and fertility in the mouse.

Dicer encodes a riboendonuclease required for microRNA biosynthesis. Dicer was inactivated in Müllerian duct mesenchyme-derived tissues of the reproductive tract of the mouse, using an Amhr2-Cre allele. Although Amhr2-Cre; Dicer conditional mutant males appeared normal and were fertile, mutant females were infertile. In adult mutant females, there was a reduction in the size of the oviducts and uterine horns. The oviducts were less coiled compared to controls and cysts formed at the isthmus near the uterotubal junction. Unfertilized, degenerate oocytes were commonly found within these cysts, indicating a defect in embryo transit. Beads transferred into the mutant oviduct failed to migrate into the uterus. In addition, blastocysts transferred directly into the mutant uterus did not result in pregnancy. Histological analysis demonstrated that the mutant uterus contained less glandular tissue and often the few glands that remained were found within the myometrium, an abnormal condition known as adenomyosis. In adult mutants, there was ectopic expression of Wnt4 and Wnt5a in the luminal epithelium (LE) and glandular epithelium (GE) of the uterus, and Wnt11 was ectopically expressed in GE. These results demonstrate that Dicer is necessary for postnatal differentiation of Müllerian duct mesenchyme-derived tissues of the female reproductive tract, suggesting that microRNAs are important regulators of female reproductive tract development and fertility.

FEMALE SEXUAL MATURATION AND BLOOD PRESSURE (SECONDARY-SEX CHARACTERISTICS, GROWTH, DEVELOPMENT)

This study described the relationship of sexual maturation and blood pressure in a sample (n = 361) of white females, ages seven through 18, attending public schools in a defined area of Central Texas during October through December, 1984. Other correlates of blood pressure were also described for this sample.^ A survey was performed to obtain the data on height, weight, body mass, pulse rate, upper arm circumference and length, and blood pressure. Each subject self-assessed her secondary sex characteristics (breast and pubic hair) according to drawings of the Tanner stages of maturation. The subjects were interviewed to obtain data on personal health habits and menstrual status. Student age, ethnic group and place of residence were abstracted from school records. Parents or guardians of the subjects responded to a questionnaire pertaining to parental and subject health history and parents' occupation and educational attainment.^ In the simple linear regression analysis, sexual maturation and variables of body size were significantly (p < 0.001) and positively associated with systolic and fourth- and fifth-phase diastolic blood pressure. The demographic and socioeconomic variables were not sufficiently variant in this population to have differential effects on the relation between blood pressure and maturation. Stepwise multiple regression was used to assess the contribution of sexual maturation to the variance of blood pressure after accounting for the variables of body size. Sexual maturation (breast stage) along with weight, height and body mass remained in the multiple regression models for fourth- and fifth-phase diastolic blood pressure. Only height and body mass remained in the regression model for systolic blood pressure; sexual maturation did not contribute more to the explanation of the systolic blood pressure variance.^ The association of sexual maturation with blood pressure level was established in this sample of young white females. More research is needed first, to determine if this relationship prevails in other populations of young females, and second, to determine the relationship of sexual maturation sequence and change with the change of blood pressure during childhood and adolescence. ^

The effect of elevated CO2 and increased temperature on in vitro fertilization success and initial embryonic development of single male:female crosses of broad-cast spawning corals at mid- and high-latitude locations

The impact of global climate change on coral reefs is expected to be most profound at the sea surface, where fertilization and embryonic development of broadcast-spawning corals takes place. We examined the effect of increased temperature and elevated CO2 levels on the in vitro fertilization success and initial embryonic development of broadcast-spawning corals using a single male:female cross of three different species from mid- and high-latitude locations: Lyudao, Taiwan (22° N) and Kochi, Japan (32° N). Eggs were fertilized under ambient conditions (27 °C and 500 µatm CO2) and under conditions predicted for 2100 (IPCC worst case scenario, 31 °C and 1000 µatm CO2). Fertilization success, abnormal development and early developmental success were determined for each sample. Increased temperature had a more profound influence than elevated CO2. In most cases, near-future warming caused a significant drop in early developmental success as a result of decreased fertilization success and/or increased abnormal development. The embryonic development of the male:female cross of A. hyacinthus from the high-latitude location was more sensitive to the increased temperature (+4 °C) than the male:female cross of A. hyacinthus from the mid-latitude location. The response to the elevated CO2 level was small and highly variable, ranging from positive to negative responses. These results suggest that global warming is a more significant and universal stressor than ocean acidification on the early embryonic development of corals from mid- and high-latitude locations.