Pubertal weight gain in female rhesus macaques

Area of Science:

• Primate reproductive biology
• Animal growth and development

Background:

• Understanding pubertal development in non-human primates is crucial for comparative biology.
• Female rhesus monkeys (Macaca mulatta) undergo menarche around 2.6 years of age.

Purpose of the Study:

• To precisely define the timing and magnitude of accelerated weight gain during puberty in female rhesus monkeys.
• To differentiate pubertal growth patterns from general growth trajectories.

Main Methods:

• Analysis of a large dataset (>10,000 records) of female rhesus monkey weights from 1.5 to 3.0 years.
• Cross-sectional linear regression to identify periods of accelerated weight increase.
• Longitudinal analysis of individual growth velocity.
• Nonlinear modeling using the Gompertz function.

Main Results:

• A significant acceleration in weight gain was observed between 196-231 weeks (28-33 months), with weights increasing by 381 g/12 weeks.
• Individual growth velocity peaked at approximately 29.7 months, averaging 499 g/12 weeks.
• The Gompertz model indicated that decelerating growth rates typical of earlier ages were not present during this pubertal acceleration phase.

Conclusions:

• Puberty in female rhesus monkeys is marked by a distinct period of accelerated weight gain.
• This growth spurt is characterized by rapid weight increase and high individual growth velocity.
• The growth pattern during this period deviates from earlier decelerating growth trends.