scholarly journals Husbandry, reproduction and postnatal development of the Neotropical muroid rodent Zygodontomys brevicauda

1992 ◽  
Vol 26 (1) ◽  
pp. 38-46 ◽  
Author(s):  
Robert S. Voss ◽  
Paul D. Heideman ◽  
Victoria L. Mayer ◽  
Thomas M. Donnelly
Keyword(s):  
Sexual Dimorphism ◽  
Postnatal Development ◽  
Experimental Research ◽  
Quantitative Genetics ◽  
Reproductive Physiology ◽  
Laboratory Colonies ◽  
Sexually Mature ◽  
Muroid Rodent ◽  
Microbiological Status

Laboratory colonies of the Neotropical muroid rodent Zygodontomys brevicauda have been employed in studies of arbovirus epidemiology and are currently the subjects of experimental research on tropical mammalian reproductive physiology and evolutionary quantitative genetics. Captive-bred litters typically consist of 4 or 5 pups weighing 3-4 g each at birth. Adults 20-40 weeks old average 60-80 g with some sexual dimorphism. Females are sexually mature at 3-4 weeks of age, males at 6-8 weeks. Ovulation is spontaneous and gestation is 25 days. Preliminary observations are provided on the microbiological status and parasites of captive-bred animals.

Quantitative genetics of sexual dimorphism in body fat measurements

1993 ◽  
Vol 5 (6) ◽  
pp. 725-734 ◽  
Author(s):  
Anthony G. Comuzzie ◽  
John Blangero ◽  
Michael C. Mahaney ◽  
Braxton D. Mitchell ◽  
Michael P. Stern ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Body Fat ◽  
Quantitative Genetics

Effects of hexarelin (a ghrelin analogue) on fertilisation and the pre- and postnatal development of mice

2010 ◽  
Vol 22 (6) ◽  
pp. 926 ◽  
Author(s):  
E. M. Luque ◽  
V. P. Carlini ◽  
L. M. Vincenti ◽  
P. Puechagut ◽  
G. Stutz ◽  
...  
Keyword(s):  
Postnatal Development ◽  
Embryo Development ◽  
Sexual Development ◽  
Reproductive Physiology ◽  
Female Mice ◽  
Impaired Memory ◽  
Adult Mice ◽  
Entire Pregnancy ◽  
Pregnant Mice ◽  
Memory Acquisition

Ghrelin (Ghr) has been associated with reproductive physiology and pre- and postnatal development. The objectives of the present study were to evaluate the effects of hexarelin (HEX; 100 or 200 µg kg−1 day−1), a therapeutic Ghr analogue, on: (1) embryo development 60 h post ovulation, induced pharmacologically, in pregnant mice; (2) the physical, neurobiological and sexual development of offspring of female mice injected with HEX during the first, second or third week of pregnancy or throughout the entire pregnancy; and (3) adult memory acquisition in these offspring. We also evaluated the effects of chronic HEX administration on memory acquisition in adult mice. Treatment of non-pregnant female mice with HEX decreased ovulation rate. However, treatment of pregnant mice with HEX at any time during pregnancy tended to accelerate offspring maturation, regardless of bodyweight. This effect was only significant on neurobiological parameters following treatment during the first week. HEX treatment during the first week and/or throughout the entire pregnancy resulted in impaired memory acquisition in the offspring, with female mice being more susceptible to these effects. Similar results were observed for the effects of chronic HEX treatment on memory acquisition in adult mice. In conclusion, HEX seems to exert differential effects depending on when it is administered. Because HEX has started to be used therapeutically, its deleterious effects on ovulation and memory acquisition must be further evaluated.

scholarly journals Gonad-related factors promote muscle performance gain during postnatal development in male and female mice

2017 ◽  
Vol 313 (1) ◽  
pp. E12-E25 ◽  
Author(s):  
Vanessa Ueberschlag-Pitiot ◽  
Amalia Stantzou ◽  
Julien Messéant ◽  
Megane Lemaitre ◽  
Daniel J. Owens ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Postnatal Development ◽  
Muscle Fiber ◽  
Muscle Performance ◽  
Performance Gain ◽  
Related Factors ◽  
Muscle Weight ◽  
Male And Female ◽  
Female Mice ◽  
Muscle Contractile

To better define the role of male and female gonad-related factors (MGRF, presumably testosterone, and FGRF, presumably estradiol, respectively) on mouse hindlimb skeletal muscle contractile performance/function gain during postnatal development, we analyzed the effect of castration initiated before puberty in male and female mice. We found that muscle absolute and specific (normalized to muscle weight) maximal forces were decreased in 6-mo-old male and female castrated mice compared with age- and sex-matched intact mice, without alteration in neuromuscular transmission. Moreover, castration decreased absolute and specific maximal powers, another important aspect of muscle performance, in 6-mo-old males, but not in females. Absolute maximal force was similarly reduced by castration in 3-mo-old muscle fiber androgen receptor (AR)-deficient and wild-type male mice, indicating that the effect of MGRF was muscle fiber AR independent. Castration reduced the muscle weight gain in 3-mo mice of both sexes and in 6-mo females but not in males. We also found that bone morphogenetic protein signaling through Smad1/5/9 was not altered by castration in atrophic muscle of 3-mo-old mice of both sexes. Moreover, castration decreased the sexual dimorphism regarding muscle performance. Together, these results demonstrated that in the long term, MGRF and FGRF promote muscle performance gain in mice during postnatal development, independently of muscle growth in males, largely via improving muscle contractile quality (force and power normalized), and that MGFR and FGRF also contribute to sexual dimorphism. However, the mechanisms underlying MGFR and FGRF actions remain to be determined.

scholarly journals Reproductive biology and sexual dimorphism in Cnemidophorus vacariensis (Sauria, Teiidae) in the grasslands of the Araucaria Plateau, southern Brazil

2009 ◽  
Vol 99 (1) ◽  
pp. 82-91 ◽  
Author(s):  
Fabíola M. Rezende-Pinto ◽  
Laura Verrastro ◽  
Juliana C. Zanotelli ◽  
Paulo C. R. Barata
Keyword(s):  
Sexual Dimorphism ◽  
Environmental Factors ◽  
Clutch Size ◽  
Morphological Characteristics ◽  
Rio Grande ◽  
Reproductive Season ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Threatened Fauna ◽  
Sexually Mature

The reproductive cycle and sexual dimorphism of the lizard Cnemidophorus vacariensis Feltrim & Lema, 2000 were studied on the basis of data gathered between August 2004 and August 2006 in Vacaria, Rio Grande do Sul, Brazil. Snout-vent length (SVL) of sexually mature males varied between 48.8 and 72.9 mm (x = 63.3 ± 6.0 mm; n = 76) and, for females, between 57.4 and 81.8 mm (x = 70.0 ± 5.9 mm; n = 73). Other morphological characteristics were also compared between sexes. Reproduction was seasonal, and observations indicate two clutches in the same reproductive season. Clutch size and other reproductive characteristics were analyzed as well as the relation between reproduction and environmental factors. Cnemidophorus vacariensis is apparently endemic to highland plateaus in southern Brazil and has been classified as vulnerable on some lists of threatened fauna in this country. Some suggestions for conservation measures are presented, due to the observed degradation of this species' environment.

scholarly journals Differences in Pelvic Fin Length Represent Sexual Dimorphism in Utah Chub (Gila atraria)

2014 ◽  
Vol 7 (1) ◽  
pp. 42-45 ◽  
Author(s):  
Mark C. Belk ◽  
Scott Bird ◽  
Mehmet Cemal Oguz ◽  
Jerald B. Johnson
Keyword(s):  
Body Size ◽  
Sexual Dimorphism ◽  
Cyprinid Fish ◽  
Sexually Dimorphic ◽  
Adaptive Function ◽  
Males And Females ◽  
The Difference ◽  
Sexually Mature ◽  
Fin Length ◽  
Pelvic Fin

The cyprinid fish Gila atraria Girard (Utah chub) is generally considered a sexually monomorphic species. However, prior observations revealed variation in pelvic fin length within populations that appears sexually dimorphic. We measured the relative pelvic fin length of 419 sexually mature Utah chub from 8 different locations to determine the magnitude and generality of this apparent dimorphism. Pelvic fin length in G. atraria differs between sexes by about 10% on average; males have longer pelvic fins than females. The dimorphism is general across all locations, but it is not related to body size. Magnitude of the dimorphism varies by predation environment – the difference between males and females is slightly greater in low predation environments. We find no evidence for an adaptive function for this dimorphism; however, it does provide an efficient mechanism for determining sex without dissection.

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