Genetics and caging type affect birth weight in captive pigtailed macaques (Macaca nemestrina)

Area of Science:

• Primate Genetics
• Quantitative Genetics
• Animal Breeding

Background:

• Birth weight is a critical indicator of neonatal health and development.
• Understanding the genetic and environmental influences on birth weight is crucial for both animal and human health.
• Previous studies in humans are often confounded by complex environmental and social factors.

Purpose of the Study:

• To estimate the heritability of birth weight in captive pigtailed macaques.
• To quantify the contributions of additive genetic, cytoplasmic genetic, and environmental effects on birth weight.
• To utilize a nonhuman primate model to overcome confounding variables present in human studies.

Main Methods:

• Quantitative genetic analyses using statistical variance decomposition.
• Utilized 30 years of breeding and pedigree records from 3,562 pigtailed macaques.
• Model incorporated additive genetic, cytoplasmic genetic, birth environment, shared maternal environment, and unmeasured environmental effects.

Main Results:

• Overall heritability of birth weight was estimated at 0.51 (h(2)).
• Significant additive genetic heritability (h(2) = 0.23) and cytoplasmic heritability (h(2) = 0.09) were identified.
• Birth location and cage type explained an additional 6% of birth weight variance.

Conclusions:

• Birth weight in pigtailed macaques exhibits a strong heritable component.
• Both genetic (additive and cytoplasmic) and specific environmental factors influence birth weight.
• This primate model provides valuable insights into the genetic architecture of birth weight, applicable to understanding human traits.