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Objective To identify chromosomal regions harboring quantitative trait loci for waist circumference (WC) and body mass index (BMI). Design and Methods A genome-wide linkage scan and regional association study WC and BMI among 633 Chinese families was conducted. Results A significant linkage signal for WC was observed at 22q13.31-22q13.33 in the overall analysis (LOD = 3.13). Follow-up association study of 22q13.31-13.33 revealed an association between the TBC1D22A gene marker rs16996195 and WC (false discovery rate [FDR]-Q < 0.05). In gender-stratified analysis, suggestive linkage signals were attained for WC at 2p24.3-2q12.2 and 22q13.33 among females (LOD = 2.54 and 2.15, respectively). Among males, 6q12-6q13 was suggestively linked to BMI (LOD = 2.03). Single marker association analyses at these regions identified male-specific relationships of six single nucleotide polymorphisms (SNPs) at 2p24.3-2q12.2 (rs100955, rs13020676, rs13014034, rs12990515, rs17024325, and rs2192712) and five SNPs at 6q12-6q13 (rs7747318, rs7767301, rs12197115, rs12203049, and rs9454847) with the obesity-related phenotypes (all FDR-Q < 0.05). At chromosome 6q12-6q13, markers rs7755450 and rs11758293 predicted BMI in females (both FDR-Q < 0.05). Conclusions Genomic regions on chromosomes 2, 6, and 22 which may harbor important obesity-susceptibility loci were described. Follow-up study of these regions revealed several novel variants associated with obesity related traits. Future work to confirm these promising findings is warranted. [ABSTRACT FROM AUTHOR]

This report compares estimated gestational ages from published cubic spline curves to gestational ages estimated retrospectively from delivery dates in 28 pregnancies from ten common marmosets (Callihrix jacchus). Both CRL- and BPD-based estimates of gestational age were closely correlated with delivery-based gestational age estimates. Of the three ultrasound machines used, the one with 16 shades of gray and a sequential linear array overestimated gestational age during early pregnancy, based on CRL measures. Measures from the other two machines (64 or 264 shades of gray; linear sector and annular array or electronic phase array) were similar and resulted in a correlation of the two estimates of gestational age of 0.94 and a mean difference between the two estimates of 0.16 days with 80% of CRL-based gestational age estimates being within ± 5 days of the delivery-based estimate. The reliability of BPD-based estimates of gestational age was strongly related to pregnancy outcome. BPD-based estimates underestimated gestational age in poor outcome pregnancies (i.e., those in which infants died within 7 days of birth) but not in good outcome pregnancies. The combined CRL- and BPDbased estimates on poor outcome pregnancies suggest that there was less growth in BPD in late gestation for those pregnancies that resulted in nonviable offspring. For good outcome pregnancies, the correlation between BPD-based and delivery-based estimates of gestational age was 0.871 and the mean difference between the two estimates was -0.06 days with 83.3% of BPD-based estimates falling within ± 5 days of delivery-based estimates. [ABSTRACT FROM AUTHOR]

Adult body mass and changes in mass during an individual's life are important indicators of general health and reproductive fitness. Therefore, characterization of the factors that influence normal variation in body mass has important implications for colony management and husbandry. The main objective of this study was to quantify the genetic contribution to adult body mass and its maintenance in baboons. Intra-individual mean and variance in body mass were calculated from multiple weight measures available for each of 1,614 animals at least 10 years of age. Heritabilities were estimated using maximum likelihood methods. Mean adult body mass had a significant heritability (50%) as did variance in adult body mass (12%). The sexes differed in several respects: on average females were smaller than males and had greater variability in adult body mass; mean and variance in body mass increased with age in females only; and number of offspring showed a significant positive relationship with body mass in females only. There were significant differences between subspecies in body mass as well as ability to maintain body mass. These results indicate that there is a significant genetic influence on body mass and its maintenance, and suggest that different factors influence changes in body mass with age as well as body mass maintenance in male and female baboons. Am. J. Primatol. 42:281–288, 1997. © 1997 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The relation between number of ovulations and body weight, age or maternal identity was examined in 69 ovarian cycles from 29 captive-born common marmoset monkeys (Callithrix jacchus ). Specifically, we addressed the following questions: was there high repeatability of ovulation number? Most of the variation in ovulation number was within, rather than between subjects. Repeatability in number of ovulations was 0.081 (n = 20 females with 2–6 ovulatory cycles per female); was age related to number of ovulations? There was no relation between age and number of ovulations, either within or between subjects; and was weight related to number of ovulations? Weight was related to number of ovulations. When the relation between number of ovulations (1–2 versus 3–4) and weight was examined through a logistic regression, there was a significant relation. Also, of the 11 subjects which had a variable number of ovulations across cycles, 90.9% were heavier when ovulating 3–4 than when ovulating 2. These results are discussed as the basis for the proposal that callitrichid primates may have been selected for potential variation in reproductive output and that this variation may be related to energy availability. Am. J. Primatol. 42:323–329, 1997. © 1997 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The effect of hybridization on infant survival was investigated in subspecific crosses of the saddle-back tamarin (Saguinus fuscicollis) at the Oak Ridge Associated Universities (ORAU) Marmoset Research Center (Oak Ridge, TN). Cox Proportional Hazards Regression was used to compare infant survival between 1) pure subspecies, 2) F1, F2, and backcrossed hybrids, and 3) hybrids and their parental subspecies. Also, effects of management changes, sex, and litter size on infant survival were investigated. There were no significant differences in infant survival between the pure subspecies. Also, degree of hybridization (F1, F2, or backcross) did not have a significant effect on infant survival. Progeny of hybrid crosses between S. f. lagonotus and S. f. illigeri was found to have significantly (P < 0.05) higher infant survival than both of their parental subspecies. Individuals born after diet and management changes in the colony had significantly (P < 0.05) higher survival than those born before. There were no significant sex differences in infant survival. Individuals born into triplet litters had significantly (P < 0.05) lower survival than those born into twin litters. These results show heterosis (hybrid vigor) for infant survival in one subspecific S. fuscicollis cross (S.f. lagonotus × S.f. illigeri). The results suggest genetic divergence between the subspecies populations and possible reproductive isolation in the wild. [ABSTRACT FROM AUTHOR]

The increasing use of non-human primates to study fetal development and neonatal management has necessitated the availability of fetuses of known gestational history. In this study, prenatal development and growth were investigated in the common marmoset (Callithrix jacchus) using ultrasound. The objectives of this study were: (1) to determine the accuracy of ultrasound for monitoring prenatal growth and development in common marmosets, (2) to determine if litter size influences prenatal growth trajectories, and (3) to assess growth discordancy among litter mates. Fifty pregnancies were monitored longitudinally using real-time abdominal sonography. During each examination the number of fetuses was recorded, and crown-rump length (CRL) and biparietal diameter (BPD) were measured. The results indicate that ultrasound is a reliable method for observation of gross morphological changes during prenatal development in this species. Measures of CRL and BPD taken early in gestation using ultrasound were in agreement with those from gross specimens. Triplets were significantly (P < 0.05) smaller than twins for both BPD and CRL. No significant relationship was found between litter size and within litter variation in CRL or BPD. This study is the first longitudinal investigation of prenatal growth and development in C. jacchus. The observations from this study will be of use for determining approximate gestational age of fetuses, as well as providing guidelines for routine monitoring of pregnancy in this species. © 1995 Wiley-Liss, Inc., (Copyright © 1995 Wiley-Liss, Inc., A Wiley Company.)