Exteroceptive Factors, Sexual Maturation and Reproduction in the Female Rat

1979 ◽  
Vol 13 (3) ◽  
pp. 283-286 ◽  
Author(s):  
M. L. Norris ◽  
C. E. Adams
Keyword(s):  
Reproductive Performance ◽  
Sexual Maturation ◽  
Sexual Maturity ◽  
Mature Male ◽  
Female Rat ◽  
Vaginal Opening ◽  
Sexually Mature

Summary Keeping a sexually mature male with a weanling female rat advanced neither the time of vaginal opening nor that of 1st oestrus. In 2 of 3 experiments females kept singly after weaning reached sexual maturity significantly earlier than did grouped females. The reproductive performance of females mated at 1st oestrus was not significantly different from that of older primiparae. 26 rats gave birth to an average of 9·3 young at 59·5 days of age, and 22 of them reared 96% of the young to weaning.

REPRODUCTIVE PERFORMANCE IN THE ALLOXAN DIABETIC FEMALE RAT

1960 ◽  
Vol XXXIII (II) ◽  
pp. 175-184 ◽  
Author(s):  
A. M. Lawrence ◽  
A. N. Contopoulos
Keyword(s):  
Reproductive Performance ◽  
Sexual Maturity ◽  
Diabetic Rats ◽  
Female Rat ◽  
Foetal Death ◽  
Sexually Mature

ABSTRACT Sexual maturity was delayed in prepuberal rats rendered diabetic by alloxan; this could not be attributed to inanition alone. Mature rats rendered diabetic ceased to have cyclic oestrous periods, and the ovaries, uterus, and vagina involuted. Insulin restored the oestrous cycles and fertility to normal in the sexually mature alloxan diabetic rats. When the insulin was withdrawn after breeding some diabetic rats successfully delivered viable litters. In the majority, however, foetal death and resorption occurred about the 10th day of gestation. The lactational performances in alloxan-diabetic rats was variable and subnormal. This variability in reproductive performance probably accounts for the lack of agreement in the literature. No obvious correlation existed between the degree of hyperglycaemia in rats which maintained pregnancy and in those which failed to deliver viable young.

Integrated analysis of sexual maturation through successive growth instars in the spider crab Leurocyclus tuberculosus (Decapoda: Majoidea)

2017 ◽  
Vol 95 (7) ◽  
pp. 473-483 ◽  
Author(s):  
Ximena González-Pisani ◽  
Pedro J. Barón ◽  
Laura S. López Greco
Keyword(s):  
Sexual Maturation ◽  
Sexual Maturity ◽  
Carapace Width ◽  
Integrated Analysis ◽  
Growth Stages ◽  
Spider Crab ◽  
Size At Maturity ◽  
Frequency Distributions ◽  
The Right ◽  
Sexually Mature

An integrative analysis of sexual maturity associated with growth was developed for the spider crab Leurocyclus tuberculosus (H. Milne Edwards and Lucas, 1842). Sexual maturity was characterized based on gonadal, morphological, morphometric, and functional sexual maturity. Progress in sexual maturation was described through 13 growth stages (instars) detected by the examination of size (carapace width) frequency distributions. Mature females displayed mature ovaries, developed vaginae, open gonopores, allometric changes in the abdomen, and ovigerous stage in the transition from instar IX to instar X. Sexually mature males presented spermatophores in the distal vasa deferentia and allometric changes in several measurements of the right chela in the transition from instar X to instar XI. However, two prepubertal phases were recognized in both sexes separated from each other by a prepubertal critical molt. Preceding the second critical molt, gonopores were sealed and vasa deferentia showed no spermatophores, and therefore neither sex was able to mate. The integrated analysis of size at maturity and size frequency distributions showed that in both sexes molt to gonadal, morphological, morphometric, and functional sexual maturity occurred in advance of the terminal molt, in contrast with patterns observed in other Majoidea.

scholarly journals The effect of different lightning programs on reproductive performance of native turkeys

2009 ◽  
Vol 2009 ◽  
pp. 232-232
Author(s):  
S M Shakooryi ◽  
E Abdi Ghezeljeh ◽  
M Danesh Mesgaran ◽  
S A Mirghelenj
Keyword(s):  
Reproductive Performance ◽  
Sexual Maturation ◽  
Sexual Maturity ◽  
Metabolic Disorders ◽  
Constant Light ◽  
Life Period ◽  
Lighting Intensity

Lighting is very important for turkey production, because their life period is longer than poultry (Nixey 1994). One of the important effects of lighting is to change the time of sexual maturity in pullets. Classen et al. (1994) concluded that constant light causes an increase incidence of leg problem and metabolic disorders. With lighting programs and lighting intensity, time of sexual maturation can be modified. Because there is little information about lighting programs in native turkey production in Iran, the aim of this research is determining the best lighting program for native turkey production.

FACTORS INFLUENCING SEXUAL MATURATION, PUBERTY AND REPRODUCTIVE EFFICIENCY IN THE GILT

1988 ◽  
Vol 68 (1) ◽  
pp. 1-13 ◽  
Author(s):  
G. W. DYCK
Keyword(s):  
Litter Size ◽  
Sexual Maturation ◽  
Sexual Maturity ◽  
Easy Method ◽  
Younger Age ◽  
Management Procedures ◽  
Short Period ◽  
The Many ◽  
Age Range ◽  
Sexually Mature

Sexual development of the gilt involves the three distinct phases of sexual maturation, attainment of puberty, and pregnancy. Our knowledge of sexual maturation is at the stage of understanding the process, while puberty and pregnancy are at the stage of manipulation to improve efficiency. The developmental changes associated with sexual maturation are indicative of an orderly sequence of hormonal and anatomical changes that lead to puberty. This process is completed at an average age of 140 d (range > 80 d) and is followed by a "resting" period to the time of puberty. The reasons for variability in the rate of development are unknown and there is no easy method of determining when a gilt is sexually mature. In contrast, puberty is easily defined and occurs an average of 60 d after "completion" of prepubertal development (age range > 100 d). While it is not possible to substantially reduce age at puberty except by selection, puberty can be delayed by dietary intake restriction and by confinement housing (no movement or exposure to mature boars). When gilts are moved and exposed to mature boars, they will be in estrus in a short period of time provided that they have attained sexual maturity. Attempts to induce puberty with hormone injections at a younger age have not been effective because of the variability in age at sexual maturity. Research on the many facets of pregnancy has resulted in development of nutritional and mating management procedures to maximize ovulation rate, pregnancy rate and conception rate. However, there has been little change in litter size at birth, suggesting that the size of the uterus may ultimately limit litter size. Survival of the piglets born can be substantially improved by assisting the gilt during parturition and careiully managing the gilt and litter during lactation. The efficiency of management has been greatly increased by the use of prostaglandin analogues to control the time of parturition. Key words: Gilts, sexual maturation, puberty, litter size

scholarly journals Delayed Neuroendocrine Sexual Maturation in Female Rats After a Very Low Dose of Bisphenol A Through Altered GABAergic Neurotransmission and Opposing Effects of a High Dose

Endocrinology ◽  
2016 ◽  
Vol 157 (5) ◽  
pp. 1740-1750 ◽  
Author(s):  
Delphine Franssen ◽  
Arlette Gérard ◽  
Benoit Hennuy ◽  
Anne-Françoise Donneau ◽  
Jean-Pierre Bourguignon ◽  
...  
Keyword(s):  
Bisphenol A ◽  
Sexual Maturation ◽  
Low Dose ◽  
Ex Vivo ◽  
Female Rats ◽  
High Dose ◽  
Sequencing Analysis ◽  
Female Rat ◽  
Vaginal Opening ◽  
Gabaergic Neurotransmission

Abstract Rat sexual maturation is preceded by a reduction of the interpulse interval (IPI) of GnRH neurosecretion. This work aims at studying disruption of that neuroendocrine event in females after early exposure to a very low dose of bisphenol A (BPA), a ubiquitous endocrine disrupting chemical. Female rats were exposed to vehicle or BPA 25 ng/kg·d, 25 μg/kg·d, or 5 mg/kg·d from postnatal day (PND)1 to PND5 or PND15. Exposure to 25 ng/kg·d of BPA for 5 or 15 days was followed by a delay in developmental reduction of GnRH IPI studied ex vivo on PND20. After 15 days of exposure to that low dose of BPA, vaginal opening tended to be delayed. In contrast, exposure to BPA 5 mg/kg·d for 15 days resulted in a premature reduction in GnRH IPI and a trend toward early vaginal opening. RNA sequencing analysis on PND20 indicated that exposure to BPA resulted in opposing dose effects on the mRNA expression of hypothalamic genes involved in gamma aminobutyric acid A (GABAA) neurotransmission. The study of GnRH secretion in vitro in the presence of GABAA receptor agonist/antagonist confirmed an increased or a reduced GABAergic tone after in vivo exposure to the very low or the high dose of BPA, respectively. Overall, we show for the first time that neonatal exposure to BPA leads to opposing dose-dependent effects on the neuroendocrine control of puberty in the female rat. A very low and environmentally relevant dose of BPA delays neuroendocrine maturation related to puberty through increased inhibitory GABAergic neurotransmission.

Changes in lysosomal enzymes and mannose-6-phosphate receptors related to sexual maturation in bull epididymis

2016 ◽  
Vol 28 (10) ◽  
pp. 1608
Author(s):  
Andrea C. Aguilera ◽  
Lorena Carvelli ◽  
Verónica Boschin ◽  
Fabián Mohamed ◽  
Leila Zyla ◽  
...  
Keyword(s):  
Male Infertility ◽  
Sexual Maturation ◽  
Molecular Basis ◽  
Sexual Maturity ◽  
Lysosomal Enzymes ◽  
Sperm Maturation ◽  
Different Ages ◽  
Mannose 6 Phosphate ◽  
Sexually Mature

One of the most striking features of the mammalian epididymis is the secretion of lysosomal enzymes (LE). These LE may play a role in sperm maturation. In the present study we investigated the activity and distribution of four LE (β-galactosidase (β-Gal), N-acetyl-β-D-glucosaminidase (β-NAG), α-mannosidase (α-Man) and β-glucuronidase (β-Glu)) in bull epididymis at two different ages (6 months and 4 years) to determine whether these enzymes vary with sexual maturity. In young, sexually immature (SI) bulls we found high LE activity in the epididymal tissue that accounts for a developed and active lysosomal apparatus. In contrast, low LE activity was measured in sexually mature (SM) bulls, and β-NAG and β-Gal were mostly secreted into the lumen. We also attempted to correlate LE distribution with the expression and functionality of mannose-6-phosphate receptors (MPRs), which are thought to be involved in proper delivery of LE to lysosomes. The cation-dependent MPR was highly expressed in SI bulls, with expression decreasing during adulthood, whereas the expression of the cation-independent MPR was higher in SM than SI bulls. In addition, the four enzymes recovered from the epididymal lumen interact with both MPRs at each age. We conclude that the activity and distribution of LE in bull epididymis varies with sexual maturity and that the distribution is regulated differently by the two types of MPR. These findings could provide some molecular basis for male infertility.

RETARDATION OF FIRST OVULATION IN PUBERTAL RATS AFTER TREATMENT WITH 5α-ANDROSTANE-3α,17β-DIOL OR ITS 3β-EPIMER

1982 ◽  
Vol 92 (1) ◽  
pp. 31-35 ◽  
Author(s):  
P. KRAMER ◽  
H. M. A. MEIJS-ROELOFS
Keyword(s):  
Body Weight ◽  
Precocious Puberty ◽  
Sexual Maturation ◽  
Female Rats ◽  
Female Rat ◽  
Vaginal Opening ◽  
Significant Delay ◽  
Vaginal Smears ◽  
Immature Female ◽  
High Doses

The effect was studied of five daily injections of 50 μg of either 5α-androstane-3α,17β-diol (3α-androstanediol) or its 3β-epimer (3β-androstanediol), starting on day 22 of life, on sexual maturation in female rats. No difference was found in the age and body weight at first oestrus between oil-treated rats and rats treated with either 3α- or 3β-androstanediol. The only difference observed between these groups consisted of the occurrence of a 'pinhole' vaginal opening a few days before oestrus in 50% of the steroid-treated rats; in oil-treated rats immediate full vaginal opening and first oestrus coincided in ten out of 12 rats. Different effects were obtained when the higher dose of 100 μg daily was used; effects were dissimilar in rats treated with 3α- and 3β-androstanediol. If administration of the higher dose of 3β-androstanediol was started on day 22 and continued until the day of full vaginal opening and first oestrus, a significant delay of this first oestrus, preceded by a few days of a 'pinhole' type of vaginal opening, was observed. After administration of the higher dose of 3α-androstanediol a 'pinhole' type of vaginal opening, accompanied by dioestrous-like vaginal smears, was also found, but oestrus did not occur during the period when injections were given. After the injections were stopped on day 45, first oestrus developed within 6 days in all rats. The previous findings of others that administration of 3β-androstanediol to the immature female rat may induce precocious puberty (i.e. precocious vaginal opening and first ovulation) were not confirmed in the present study. Our results indicate that high doses of free 3α-androstanediol, and to a lesser degree 3β-androstanediol, may even delay first ovulation in the rat. A possible interference of 3α-androstanediol with the triggering of the first ovulatory gonadotrophin peaks is discussed.

The first report of albinism in a Sundaland endemic rodent

Mammalia ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jonathan A. Nations ◽  
Ahmad Mursyid ◽  
Ryski Darma Busta ◽  
Sah Putra Adrian ◽  
Heru Handika ◽  
...  
Keyword(s):  
Southeast Asia ◽  
Mature Male ◽  
Congenital Disorder ◽  
Domesticated Animals ◽  
First Report ◽  
West Sumatra ◽  
Sexually Mature

AbstractAlbinism, a congenital disorder that results in a lack of melanin deposition, is common in domesticated animals but rare in nature. Among the ∼2500 species of rodents worldwide, only 67 have published reports of albinism. Here we report the capture of an albino murid (Muridae: Rodentia) from Mt. Singgalang in West Sumatra, Indonesia. The specimen is an adolescent but sexually mature male Maxomys hylomyoides, a montane Sumatran endemic. To our knowledge, this specimen represents the first reported albino rodent from Indonesia and Sundaland, and only the second from Southeast Asia.

Akodon molinae (Rodentia Cricetidae), a new laboratory animal: breeding, management and reproductive performance

1980 ◽  
Vol 14 (2) ◽  
pp. 129-131 ◽  
Author(s):  
Maria Susana Merani ◽  
Marta Susana Lizarralde
Keyword(s):  
Sex Ratio ◽  
Reproductive Performance ◽  
Sexual Maturity ◽  
Laboratory Animal ◽  
Post Partum ◽  
Animal Breeding ◽  
Haemorrhagic Fever ◽  
Sex Ratio At Birth ◽  
Breeding Management ◽  
Laboratory Colony

Akodon molinae, a vole mouse widely distributed in central Argentina, shows remarkable chromosome polymorphisms. It is one of the natural reservoirs of the actiologic agent of haemorrhagic fever, and a laboratory colony could be of great help in investigating this disease. Pregnancy lasted 23 (range 21-25) days. Litters of 4-5 young were born to monogamous breeding pairs about every 30 days, with weaning at 26 days post partum. The sex ratio at birth was 505 males to 500 females: at weaning it was 460 to 440. Sexual maturity was attained at about 16 weeks of age in males and 12-20 weeks in females. Akodon molinae is easy to handle, but fighting and killing or neglect of young are problems.

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