scholarly journals Chromosome behaviour in the male ferret and mole during anoestrus

1936 ◽  
Vol 121 (822) ◽  
pp. 192-206 ◽  
Keyword(s):  
Seasonal Variation ◽  
Breeding Season ◽  
Reproductive Organs ◽  
Quiescent State ◽  
Chromosome Behaviour ◽  
Histological Changes ◽  
Short Period ◽  
Cytological Changes

The breeding season of many Mammals is restricted to a relatively short period of the year. In such species usually both sexes exhibit a more or less well-defined seasonal variation in their reproductive organs. Several investigators have found that these variations in the male consist chiefly of alteration in the size of the testes and epididymis, accompanied by marked histological and cytological changes leading to a complete absence of sperms during the quiescent or anoestrous period. The cyclic histological changes in the testes and in the accessory organs have been described in detail in the ferret ( Putorius furo, L .) by Allanson (1932), and in the mole ( Talpa europea, L .) by Tandler and Grosz (1912) and Allanson ( unpublished ). It was found in both genera that during the breeding season spermatogenesis is complete and very active in the rapidly growing testis, but after that period the reproductive organs return to a quiescent state and sperms are entirely absent.

XIII.—Cytological Studies on the Reproductive Organs. Chromosome Behaviour in the Male Grey Squirrel (Sciurus carolinensis leucotus)

1937 ◽  
Vol 56 ◽  
pp. 196-209 ◽  
Author(s):  
P. C. Koller
Keyword(s):  
Reproductive Organs ◽  
Economic Importance ◽  
Sciurus Carolinensis ◽  
Chromosome Behaviour ◽  
American Continent ◽  
Grey Squirrel ◽  
Histological Changes ◽  
North American Continent ◽  
The North ◽  
Great Economic Importance

The grey squirrel (Sciurus carolinensis leucotus Gapper), which is a native of the North American continent, was introduced into England and Scotland quite recently and soon became of great economic importance in these countries. In his very excellent monograph, Middleton (1930) states that both sexes of the grey squirrel show diminished activity during the winter and while they do not hibernate in the true sense of the word, they probably sleep if the weather is severe. The breeding habits of the female were studied by Deanesly and Parkes (1933), who ascertained that the female definitely has a period of anœstrus during which the reproductive organs are atrophic. In the male, however, fully functional testes were found throughout the year (Allanson, 1933), and there were no histological changes which would indicate a regular period of quiescence.

Studies on the marsupial glider, Schoinobates volans (Kerr) I. Reproduction

1969 ◽  
Vol 17 (4) ◽  
pp. 625 ◽  
Author(s):  
RFC Smith
Keyword(s):  
Natural Population ◽  
Breeding Season ◽  
Reproductive Cycle ◽  
Reproductive System ◽  
Sexual Maturity ◽  
Field Data ◽  
Reproductive Organs ◽  
Female Reproductive System ◽  
Histological Changes ◽  
Second Year

Field data were obtained during the period September 1962-January 1965 from 710 greater gliders, S. volans, in a natural population. Histological changes were observed in the reproductive tracts of another 129 animals shot during this period. S. volans has a short breeding season in March, April, and May, after which involution of the reproductive organs occurs in both sexes. The species is monovular and polyoestrous. Sexual maturity is attained by both sexes in the second year, following which breeding probably occurs annually. The female reproductive system shows several primitive and anomalous features, among which is the retention of the Wolffian ducts in the adult. The histology of ovaries, uteri, and vaginae at various stages of the reproductive cycle is briefly described.

Reproduction in Sminthopsis-Macroura (Marsupialia, Dasyuridae) .2. The Male

1990 ◽  
Vol 38 (2) ◽  
pp. 207 ◽  
Author(s):  
PA Woolley
Keyword(s):  
Breeding Season ◽  
Sexual Maturity ◽  
Binding Capacity ◽  
Reproductive Activity ◽  
Reproductive Organs ◽  
Histological Changes ◽  
Accessory Glands ◽  
Sminthopsis Macroura ◽  
Sexually Mature ◽  
Androgen Levels

The breeding season of S. macroura extends from June to February, and individual males (both wild- caught and laboratory-reared) are capable of breeding over extended periods during the breeding season, and for up to three seasons, in the laboratory. Gross and histological changes in the reproductive organs and endocrine changes in relation to reproductive activity have been investigated. Males do not appear to reach sexual maturity until the season following that in which they were born, although spermatorrhoea may commence in the season of birth. Testis and epididymis weight of these males, which commence spermatorrhoea late in the season, approximates that of sexually mature males early in the season but androgen levels and the weight of the accessory glands are low in all males except during the early months of the season. The age at which spermatorrhoea commences ranges from 141 to 350 days. The minimum scrota1 width at which it commences is 7.9 mm and the minimum body weight, 14.0 g. The onset of spermatorrhoea is not a function of age or season and in S. macroura should be used with caution as an indicator of impending sexual maturity. Maximum corticosteroid- binding capacity (MCBC) generally exceeded corticosteroid concentration and no androgen-related fall in MCBC was evident.

Pregnancy in a marsupial, the Tasmanian pademelon (Thylogale billardierii)

1999 ◽  
Vol 11 (3) ◽  
pp. 175 ◽  
Author(s):  
R. W. Rose ◽  
J. A. A. Horak ◽  
A. D. Shetewi ◽  
S. M. Jones
Keyword(s):  
Corpus Luteum ◽  
Reproductive Biology ◽  
Plasma Concentrations ◽  
Tammar Wallaby ◽  
Reproductive Organs ◽  
Model Species ◽  
Histological Changes ◽  
Plasma Progesterone ◽  
Embryonic Growth ◽  
Background Data

The Tasmanian pademelon, Thylogale billardierii, is a medium-sized wallaby that adapts well to captivity and, unlike the well-studied tammar wallaby, is capable of breeding all year round. It may, there-fore, be a useful model species for research into the reproductive biology of macropod marsupials. This paper presents necessary background data on histological changes in the reproductive organs and the rate of embryonic growth during gestation in T. billardierii. After Day 4 RPY (removal of young from the pouch) the gravid and non-gravid uteri differ significantly in some histological parameters. The corpus luteum becomes active by Day 6 RPY and is fully developed by Day 14 RPY; it begins to degenerate from Day 19 RPY. Plasma progesterone concentrations through gestation follow a pattern similar to that in the tammar wallaby. There is an early, smaller, peak at Day 5 RPY, with plasma concentrations of progesterone then falling until the larger pre-partum peak occurs several days before birth.

The reproductive cycle of the firetail gudgeon, Hypseleotris galii II. Seasonal histological changes in the testes

1973 ◽  
Vol 21 (1) ◽  
pp. 67 ◽  
Author(s):  
NJ Mackay
Keyword(s):  
Water Temperature ◽  
Breeding Season ◽  
Reproductive Cycle ◽  
Meiotic Division ◽  
Steroid Biosynthesis ◽  
Histological Changes ◽  
Late Autumn

Seasonal histological changes in the testis of H.galii are described. Spermatogenesis follows the cystic pattern common in anamniotes. Mitotic increase in spermatogonia occurs in late autumn, when photoperiod and water temperature are falling. The meiotic division of spermatocytes and subsequent changes of spermatogenesis are initiated when photoperiod and water temperature are rising and continue through the breeding season (November-January) until March, when water temperature begins to fall rapidly. The possible role of cholesterol-positive lobule boundary cells in steroid biosynthesis is discussed.

Bee glue (propolis) improves reproductive organs, sperm quality and histological changes and antioxidant parameters of testis tissues in rats exposed to excess copper

Andrologia ◽  
2020 ◽  
Vol 52 (4) ◽  
Author(s):  
Ismail Seven ◽  
Pinar Tatli Seven ◽  
Burcu Gul Baykalir ◽  
Tuba Parlak Ak ◽  
Seyma Ozer Kaya ◽  
...  
Keyword(s):  
Sperm Quality ◽  
Reproductive Organs ◽  
Histological Changes ◽  
Excess Copper ◽  
Antioxidant Parameters

The effect of exogenous melatonin and the plane of nutrition after weaning on ovulation rate in salz ewes lambing in the seasonal anoestrus

1994 ◽  
Vol 1994 ◽  
pp. 83-83
Author(s):  
L. Zarazaga ◽  
F. Forcada ◽  
J.A. Abecia ◽  
J. Mozota
Keyword(s):  
Nutritional Status ◽  
Sexual Activity ◽  
Breeding Season ◽  
Nutrient Status ◽  
Ovulation Rate ◽  
The Other ◽  
Cyclic Activity ◽  
Exogenous Melatonin ◽  
Short Period ◽  
Ovarian Cyclicity

Induction of oestrus and pregnancy in the seasonal anoestrus permits lambing during the breeding season and mating in a short period of time after weaning, but after spring lambing postpartum anoestrus is longer than it is in autumn lambing, and no breeds are able to resume cyclic activity two months after lambing. Nutrient status has been shown to be a major factor affecting the onset of ovarian cyclicity in postpartum ewes. On the other hand, melatonin implants were demonstrated to be efficient in advancing the annual breeding season, but the efficiency of this treatment could be modified by the nutritional status of the animals. The aim of this experiment was to determine the effect of exogenous melatonin, connected with the plane of nutrition after weaning, on the resumption of sexual activity and ovulation rate (OR) in a synthetic Spanish sheep breed lambing in spring.

scholarly journals Anatomical and histological changes during the oestrous cycle in the mare

1941 ◽  
Vol 130 (858) ◽  
pp. 1-23 ◽  
Keyword(s):  
Corpus Luteum ◽  
Reproductive Organs ◽  
Oestrous Cycle ◽  
Maximum Diameter ◽  
Histological Changes ◽  
Graafian Follicle ◽  
Heat Period ◽  
To Come ◽  
Time Required ◽  
Dominant Part

The mares chosen for the investigation of the changes in the reproductive organs during the oestrous cycle were kept under observation for some time before they were killed. The duration of the heat period in these animals was 7 days and the length of the dioestrus was 16 days. Ovulation takes place at about a day before the end of oestrus. The size of the ovary during the oestrous cycle is chiefly influenced by the growing Graafian follicle. The number of follicles present at different stages varies greatly. The numerous small follicles present at the beginning of oestrus disappear later in the cycle; it is suggested that this may be due to the lack of follicle-stimulating hormone. The colour of the corpus luteum varies greatly at different stages of the cycle. The rupture of the follicle is associated with some bleeding. The active stage of the corpus luteum is very short, and the maximum diameter of the corpus luteum seems to be always below that of the Graafian follicle. The greater development of the Graafian follicle, with its secretion of oestrin, in the mare leads to its playing a more important role than in the cow and the sow, in which species the corpus luteum takes a m ore dominant part in the cycle. It appears that the much longer oestrus in the mare than in the cow is due to the longer time required by the follicle to come to the surface and to break through. This is probably due to the peculiar structure of the ovary in the mare, since the ovulation, which is spontaneous, can only occur in the small ovulation fossa. No pronounced secretion stage occurs during oestrus in the Fallopian tubes.

The effect of peri-conceptual grazing of live pasture on fetal numbers in unsynchronised ewes

2014 ◽  
Vol 54 (8) ◽  
pp. 1008 ◽  
Author(s):  
S. M. Robertson ◽  
B. J. King ◽  
M. B. Allworth ◽  
J. Rummery ◽  
M. A. Friend
Keyword(s):  
Plant Species ◽  
Breeding Season ◽  
Live Feed ◽  
Short Period

Methods of increasing the number of lambs born per ewe that avoid the use of pharmaceutical methods of oestrus synchronisation but which require a short period of increased nutrition are desirable. Four separate experiments evaluated whether peri-conceptual grazing of lucerne, compared with senescent herbage or other live herbage, increased fetal numbers in unsynchronised ewes. Merino ewes that grazed lucerne pasture for 7 days before joining and for the first 7 days of a 5–6-week joining produced up to 21 extra (P < 0.05) fetuses per 100 ewes joined, compared with ewes grazing cereal stubble with minimal live herbage (Experiment 2). In Experiments 1, 3 and 4, Merino or First Cross ewes grazing either cereal stubbles or phalaris pasture with as little as 200 kg DM/ha of live herbage produced a similar (P > 0.05) number of fetuses per ewe joined as those grazing on lucerne, either because this quantity of live feed was sufficient to increase fetal numbers, or because, for Experiment 3, First Cross ewes may not have responded at the commencement of the breeding season. It is concluded that grazing live pasture for 7 days before joining and for the first 7 days of joining during the breeding season can substantially increase fetal numbers in unsynchronised ewes compared with ewes grazing stubbles containing no live herbage. The response appears to occur on a range of plant species, and a small quantity of live herbage can elicit a response. Grazing lucerne in the peri-conceptual period did not increase (P > 0.05) the proportion of non-pregnant ewes. Further studies are required to determine how early in the breeding season ewes with a distinct breeding season will respond to nutritional manipulation.

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