Examining maternal influence on OLETF rats' early overweight: insights from a cross-fostering study.
Obese female Otsuka Long Evans Tokushima Fatty (OLETF) rats display increased nursing time and frequency compared to lean LETO controls, suggesting a maternal contribution to pup preobesity. In previous studies, OLETF pups presented high adiposity, showed greater suckling efficiency, initiative and weight gain from nursing than controls throughout lactation. To further elucidate maternal-infant interactions contributing to pup preobesity, we cross-fostered pups a day after birth and examined maternal behavior. Nursing frequency decreased in OLETF dams raising LETO pups (OdLp) in the third postnatal week, while LETO dams raising OLETF pups showed no significant changes. Fat % was greater in the milk of OLETF versus LETO dams. OdLp pups showed long-term body weight (BW) increase, suggesting that maternal environment can induce BW increases even in the absence of a genetic tendency. Additionally, interaction between OLETF dams and pups produces high nursing frequency, exposing the pups to abundant high-fat milk, thus strengthening their preobese phenotype.
Life Sciences Faculty, Bar-Ilan University, Ramat Gan, Israel.
Mariana
M
Schroeder
Michal
M
Schechter
Ester
E
Fride
Timothy H
TH
Moran
Aron
A
Weller
D050154:Adiposity; D000818:Animals; D000833:Animals, Suckling / Q000523:psychology*; D005247:Feeding Behavior / Q000523:psychology*; D005260:Female; D007774:Lactation / Q000523:psychology; D008425:Maternal Behavior / Q000523:psychology*; D050177:Overweight / Q000209:etiology*; D011247:Pregnancy; D051381:Rats; D020334:Rats, Inbred OLETF / Q000254:growth & development / Q000523:psychology*; D013045:Species Specificity; D013391:Sucking Behavior; D013997:Time Factors; D015430:Weight Gain