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Differential effects of paternal presence on pup survival in two species of dwarf hamster (Phodopus sungorus and Phodopus campbelli).

https://arctichealth.org/en/permalink/ahliterature65331
Source
Physiol Behav. 1989 Mar;45(3):465-9
Publication Type
Article
Date
Mar-1989
Author
K E Wynne-Edwards
R D Lisk
Author Affiliation
Biology Department, Princeton University, NJ 08544.
Source
Physiol Behav. 1989 Mar;45(3):465-9
Date
Mar-1989
Language
English
Publication Type
Article
Keywords
Animals
Animals, Newborn - growth & development
Body Weight
Cold
Cricetinae - physiology
Female
Litter Size
Male
Mortality
Paternal Behavior
Sex Behavior, Animal - physiology
Species Specificity
Abstract
The effect of the presence or absence of the male, and of decreased ambient temperature (21 degrees C vs. 4 degrees C) on litter survival, pup survival and pup growth was measured from birth through day 18 after birth in Siberian (P. sungorus) and Djungarian (P. campbelli) hamsters. Siberian hamsters were not significantly affected by the experimental manipulations. In contrast, whereas 100% of litters and 95% of pups were successfully raised to weaning at 21 degrees C by paired Djungarian hamsters, survival fell to 47% when the mate was absent and even further, to 32%, when the ambient temperature was lowered. No significant differences in litter size or pup weight at birth were detected between species at the warmer temperature. However, P. sungorus pups gained weight significantly faster through day 12 after birth (while dependence upon the mother for food was absolute) than P. campbelli pups under all experimental conditions. Although the species are closely related, these data show that male Djungarian hamsters are essential to offspring survival under conditions where Siberian hamsters do not require conspecific help. Species differences in metabolism and thermoregulation may account for the differential pup survival.
PubMed ID
2756037 View in PubMed
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Maternal transfer of photoperiodic information in Siberian hamsters. III. Melatonin injections program postnatal reproductive development expressed in constant light.

https://arctichealth.org/en/permalink/ahliterature65298
Source
Biol Reprod. 1989 Jul;41(1):34-9
Publication Type
Article
Date
Jul-1989
Author
T H Horton
S L Ray
M H Stetson
Author Affiliation
Physiology and Anatomy Program, School of Life and Health Sciences, University of Delaware.
Source
Biol Reprod. 1989 Jul;41(1):34-9
Date
Jul-1989
Language
English
Publication Type
Article
Keywords
Animals
Cricetinae - physiology
Female
Injections
Light
Male
Maternal-Fetal Exchange
Melatonin - administration & dosage - pharmacology
Pregnancy
Reproduction - drug effects
Research Support, U.S. Gov't, Non-P.H.S.
Research Support, U.S. Gov't, P.H.S.
Testis - anatomy & histology - drug effects - embryology
Time Factors
Abstract
In Siberian hamsters, transference of photoperiodic information from dam to fetus influences pubertal testicular development of the young when reared either in constant light (LL) or postnatal photoperiods of intermediate length (i.e. 14L:10D). The effects of short photoperiods during gestation can be mimicked by administering melatonin to pregnant females. This experiment examined whether there exists a daily pattern of sensitivity to melatonin when it is administered to pineal-intact pregnant females housed on a long photoperiod. Groups of pregnant and lactating females received melatonin at each hour of the day. The young were not treated with exogenous melatonin. At the approximate time of maturation of their endogenous pineal melatonin rhythm (Day 15), the young were placed in LL to suppress pineal melatonin secretion. Young males were killed at 28 days of age. Afternoon (1200 h-2000 h) and late night (0400 h) injections of melatonin into females caused their male young to develop as though gestation occurred on a short photoperiod. Melatonin injections at other times were ineffective. The daily pattern of effectiveness of exogenous melatonin administration to pregnant females resembles that observed in adult males of this and other hamster species and is consistent with the hypothesis that a daily rhythm in sensitivity to melatonin is involved in the transduction of photoperiodic signals.
PubMed ID
2804208 View in PubMed
Less detail

Maternal transfer of photoperiodic information in Siberian hamsters. II. The nature of the maternal signal, time of signal transfer, and the effect of the maternal signal on peripubertal reproductive development in the absence of photoperiodic input.

https://arctichealth.org/en/permalink/ahliterature65330
Source
Biol Reprod. 1989 Mar;40(3):458-65
Publication Type
Article
Date
Mar-1989
Author
M H Stetson
S L Ray
N. Creyaufmiller
T H Horton
Author Affiliation
Physiology and Anatomy Program, School of Life and Health Sciences, University of Delaware, Newark 19716.
Source
Biol Reprod. 1989 Mar;40(3):458-65
Date
Mar-1989
Language
English
Publication Type
Article
Keywords
Aging
Animals
Cricetinae - physiology
Darkness
Female
Lactation
Light
Male
Maternal-Fetal Exchange
Melatonin - pharmacology
Periodicity
Pregnancy
Reproduction
Research Support, U.S. Gov't, Non-P.H.S.
Testis - growth & development
Time Factors
Abstract
Peripubertal reproductive development of Siberian hamsters is controlled by maternally derived photoperiodic information and the ambient photoperiod present after weaning. Previous experiments suggested that the maternally derived information is transferred during gestation, not during lactation. Development was examined in several photoperiods following manipulation of gestational and lactational photoperiods; development was influenced by the gestational, but not lactational, photoperiod. Second, effects of the gestational photoperiod were observed in young reared in constant light (LL) from Day 15. Depriving the young of ambient photoperiodic information after Day 15 allows a more direct assessment of the signal received from their dams. Finally, melatonin injections to long-day dams, at certain times of day, caused transmission of a short-day signal to young, as evidenced by their development in LL and light-dark cycles. Thus, a maternally derived signal that is dependent on melatonin influences reproductive development of the young during gestation; the maternally directed pattern of development can subsequently be modified by the youngs' own response to ambient photoperiods after weaning.
PubMed ID
2758085 View in PubMed
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Regional differences in fat pad responses to short days in Siberian hamsters.

https://arctichealth.org/en/permalink/ahliterature52897
Source
Am J Physiol. 1989 Dec;257(6 Pt 2):R1533-40
Publication Type
Article
Date
Dec-1989
Author
T J Bartness
J M Hamilton
G N Wade
B D Goldman
Author Affiliation
Worcester Foundation for Experimental Biology, Shrewsbury 01545.
Source
Am J Physiol. 1989 Dec;257(6 Pt 2):R1533-40
Date
Dec-1989
Language
English
Publication Type
Article
Keywords
Acclimatization
Adipose Tissue - physiology
Animals
Body Weight
Cricetinae - physiology
Darkness
Female
Light
Lipids - biosynthesis
Lipoprotein Lipase - metabolism
Male
Organ Size
Organ Specificity
Research Support, U.S. Gov't, P.H.S.
Seasons
Abstract
Siberian hamsters exhibit decreased body weight and fat after initial exposure to short photoperiods and increased body weight and fat after extended short photoperiod exposure. The purpose of the present experiments was to determine if uniform changes in white adipose tissue (WAT) pad weights and lipid metabolism correspond to these short photoperiod-induced changes in body fat. Carcass lipid content and testes and fat pad weights [retroperitoneal WAT (RWAT), epididymal WAT (EWAT), and inguinal and dorsal subcutaneous WAT, respectively] were decreased in male hamsters relative to their long day counterparts after 6 and 12 wk of short-day exposure. Moreover, EWAT and RWAT weight, EWAT specific lipoprotein lipase activity, and specific and total lipogenesis were disproportionately decreased relative to the subcutaneous fat pads. The changes in fat pad weight and metabolism were generally reversed coincident with the return to a long-day-like reproductive status after prolonged short-day exposure (24 and 30 wk). In a less detailed experiment, female Siberian hamsters had decreased body, fat pad, and uterine weights after 6 wk of short-day exposure; however, no fat pad-specific changes in weight were observed. The results of these experiments demonstrate that short-day-exposed male Siberian hamsters may be a useful model for examining mechanisms underlying fat pad-specific responses. In addition, gender appears to influence the pattern of short-day-induced lipid depletion in this species.
PubMed ID
2604008 View in PubMed
Less detail