Search USGS⌕ Search

USGS · 70238525

Coyote reproduction. I. The duration of the spermatogenic cycle and epididymal sperm transport

Abstract

Sexually mature, male coyotes were injected with [ 3 H]thymidine to estimate (1) the duration of one cycle of the seminiferous epithelium, and (2) epididymal sperm transport time. The mean duration of spermatogenic stages 1 to 8 was estimated to be 3·4, 2·1, 0·5, 1·4, 1·8, 1·7, 1·5 and 1·3 days, respectively. The total duration of one cycle of the seminiferous epithelium was 13·6 days. Radioactive spermatozoa were observed in the caput epididymidis 40 days after [ 3 H]thymidine injection, but data suggested that they may arrive as early as 37·4 days. Radioactive spermatozoa first appeared in the ejaculate of one male 52 days after [ 3 H]thymidine injection, indicating that the epididymal sperm transport time is about 14 days.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

James J. Kennelly. 1972. Coyote reproduction. I. The duration of the spermatogenic cycle and epididymal sperm transport. https://doi.org/10.1530/jrf.0.0310163

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related USGS reports

Association of seasonal reproductive patterns with changing food availability in an equatorial carnivore, the spotted hyaena (Crocuta crocuta)

Reproductive seasonalitywas examined inan equatorial populationof free-living spotted hyaenas (Crocuta crocuta) inKenya. The study population was observed continuously for 10 years, duringwhich time the dates of all births, conceptions, weanings,andcubdeathswererecorded.Local preyabundancewasestimatedtwoto four timespermonth, andrainfallwas recordeddailythroughout thestudyperiod. Birthsoccurredduringeverymonthoftheyear,butadistincttroughinbirthsoccurred fromFebruary toMay.Thistroughoccurredapproximatelyonegestationperiodafter thephaseof theannual cycleduringwhichpreyanimalswere leastabundant inthe home range of thehyaenas, andconceptionsoccurredmost frequentlywhen food abundancewasgreatest.Neitherrainfallnorcubmortalitywerecorrelatedwithbirths or conceptions.Thus,althoughspottedhyaenasarecapableofbreedingthroughoutthe year, theyexhibitamoderatedegreeofseasonalitythatmost likelyreflectsresponsesto seasonalvariationinenergyavailability.

Journal of Reproduction and Fertility↗

Oviposition and the plasma concentrations of LH, progesterone, and corticosterone in bobwhite quail (Colinus virginianus) fed parathion

Bobwhite quail were fed concentrations of parathion (0,50, 100, 200 or 400 p.p.m.) for 10 days. Food intake, body weight change, brain acetylcholinesterase activity, egg production, and ovary weight were reduced in a dose-dependent manner. In a second experiment, birds were fed 0, 25 or 100 p.p.m. parathion or pair-fed control food to equate consumption in the 100 p.p.m. group. Egg production was not affected in birds fed 25 p.p.m. or in the pair-fed group, but the daily time of oviposition was more variable than in the control group. Cessation of egg production, inhibition of follicular development, and reduced plasma LH concentration were observed in birds fed 100 p.p.m. parathion. These findings indicate that exposure to parathion can impair reproduction, possibly by altering gonadotrophin secretion.

Journal of Reproduction and Fertility↗