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PubMed1986

Ovarian steroidogenesis during follicular maturation in the domestic fowl (Gallus domesticus).

The steroidogenic potential of various physiological compartments within the ovary of the hen were examined using in vitro systems. Three-hour incubations of individual whole small follicles (less than 1 mm-1 cm) or 100,000 collagenase-dispersed theca cells of the five largest ovarian follicles (F1-F5) were conducted in 1 ml of Medium 199 at 37 degrees C in the presence and absence of luteinizing hormone (LH) (0.39, 0.78, 1.56, 3.13 and 6.25 ng), progesterone (5 ng), and dehydroepiandrosterone (DHEA, 5 ng). Steroid output was measured by radioimmunoassay of incubation media. Progesterone was not produced by small follicles although they are a major source of DHEA and estradiol and a significant source of androstenedione. Output of DHEA, androstenedione and estradiol was highly stimulated by LH. The substrate for androstenedione and estradiol in small follicles is probably DHEA. Output of DHEA and androstenedione in theca cells of F2-F5 was stimulated by LH in a dose-related manner. A dose-response relationship between estradiol output and the concentration of LH in media was not apparent in theca cells from F2-F5. Steroidogenesis in theca tissue of large follicles occurs predominantly via the delta 4 pathway. The ability of these theca cells to metabolize progesterone to androstenedione is lost between 36 and 12 h before ovulation. Their ability to metabolize DHEA to androstenedione is still present 12 h before ovulation. Aromatase activity is significantly reduced between 36 and 12 h before ovulation. These data indicate that both large and small follicles can be stimulated by LH. The small follicles are the major source of estrogen. As the large yolky follicles mature, steroidogenesis shifts from the delta 5 to the delta 4 pathway. By 12 h before ovulation, the F1 follicle has lost the ability to convert progesterone to androstenedione. The inability of the largest ovarian follicle to convert progesterone to androstenedione contributes at least in part to the preovulatory increase in the plasma concentration of progesterone that generates the preovulatory LH surge by positive feedback.

Androstenedione↗
PubMed1998

Sperm mobility: a quantitative trait of the domestic fowl (Gallus domesticus).

Sperm from each rooster within a base population (n = 271) were evaluated with a mobility assay validated in previous work. Frequency analysis confirmed a normal distribution for the variable of sperm mobility. Repeated-measure analysis of males categorized by phenotype demonstrated that average and high sperm mobility phenotypes were distinct and independent of time. Sperm morphology, fertilizing ability, and ATP content were compared between phenotypes. Fertility and sperm ATP content differed (p < 0.001) between phenotypes, whereas sperm morphology did not (p > 0.05). Experimentation with washed sperm demonstrated that phenotype was fully expressed when mitochondrial respiration was the only source of ATP. Sperm mobility increased (p < 0.001) when sperm from average males were exposed to calyculin A, a protein phosphatase inhibitor. Correlation analyses were performed with data from a subpopulation (n = 46) whose range, mean, and variance were equivalent to those of the base population. Neither body weight nor the combined weight of the testes was correlated with sperm mobility (r = -0.02 and 0.01, respectively). In contrast, sperm ATP content was correlated with sperm mobility (r = 0.80). We attribute phenotypic differences in sperm mobility to differential rates of mitochondrial ATP synthesis.

Adenosine Triphosphate↗
PubMed1986

A fourth allele in the plasma esterase-1 (Es-1) system of the domestic fowl.

Plasma samples of fowl were analysed by horizontal polyacrylamide gel electrophoresis (pH 9.0). Evidence was presented for the subdivision of an earlier reported esterase-1 allele (Es-1A) into two alleles designated Es-1A1 and Es-1A2. Family data were consistent with the hypothesis that the Es-1 phenotypes were controlled by four codominant, autosomal alleles Es-1C, Es-1A1, Es-1A2 and Es-1B). The White Leghorn samples showed high frequency of Es-1A1 (about 0.7) and also had considerable frequency of Es-1A2 (0.2) and of Es-1B (0.1). The three meat-type breeds studied (White Plymouth Rock, Rhode Island Red and New Hampshire) showed a very high frequency of Es-1B (0.8-1.0).

Alleles↗
PubMed1980

The connection between the seminiferous tubules and the rete testis in the domestic fowl (Gallus domesticus). Morphological study.

The tubules connecting the seminiferous tubules proper to the rete testis in the fowl were studied with the aid of light and electron microscopy. The material examined ultrastructurally was fixed by vascular perfusion through the thoracic aorta. The seminiferous tubules were joined to the rete testis in three different ways; they were either linked by a terminal segment and a tubulus rectus, by a terminal segment only, or opened directly into the rete cavities. The terminal segment of the seminiferous tubules was lined with columnar cells (modified Sertoli cells). These cells were characterized by having an indented nucleus with a prominent nucleolus, many mitochondria, a sizable Golgi apparatus, electron dense bodies and many cytoplasmic protrusions into the lumen. Intraepithelial lymphocytes as well as macrophages in the lumina of the terminal segment, the tubuli recti and the rete testis were also observed. Myoid cells were found in the boundary tissue of the terminal segment.

Animals↗
PubMed1980

The response of the male domestic fowl (Gallus domesticus) to alpha-chlorohydrin treatment.

Sexually mature male cockerels were treated with low and high doses of alpha-chlorohydrin for up to 30 days. Neither gross nor histological lesions were produced by the drug, and sodium, potassium and acid phosphatase levels in the testicular fluid and ductus deferential plasma were not significantly altered. All the cockerels given low doses remained fertile.

Acid Phosphatase↗
PubMed1993

Regularities and irregularities in the structure of the seminiferous epithelium in the domestic fowl (Gallus domesticus). I. Suggestion of the presence of the seminiferous epithelial cycle.

A cellular association demarcated by two perpendiculars which were drawn between adjacent bundles of elongate spermatids from the tubular lumen to the basement membrane, was made the unit of histometrical observation in this study (provisionally called a "column"). Cell counting revealed that the average numbers per column of various types of germ cells do not show any significant differences among 5 fowls and between paired testes. The frequency of spermiogenic steps (numbered 1-8) was investigated in each column. A definite and common pattern was found in the frequency distribution in the 5 fowls observed. A relationship between spermiation and younger spermatid steps was also investigated in each column. The spermiation was found at different steps, but most frequently at step 2 (30.6%). Based on these observations and referring to other author's information, an average time interval between two successive spermiations was calculated roughly at 3.3 +/- 1.2 days. Theoretically, this value is equal to an average length of one epithelial cycle. Such a variable cycle may have caused irregular cellular associations in this species.

Animals↗