Peak lactation occurs when milk production is at its highest. The factors limiting peak lactation performance have been subject of intense debate. Milk production at peak lactation appears limited by the capacity of lactating females to dissipate body heat generated as a by-product of processing food and producing milk. As a result, manipulations that enhance capacity to dissipate body heat (such as fur removal) increase peak milk production. We investigated the potential correlates of shaving-induced increases in peak milk production in laboratory mice. By transcriptomic profiling of the mammary gland, we searched for the mechanisms underlying experimentally increased milk production and its consequences for mother–young conflict over weaning, manifested by advanced or delayed involution of mammary gland. We demonstrated that shaving-induced increases in milk production were paradoxically linked to reduced expression of some milk synthesis-related genes. Moreover, the mammary glands of shaved mice had a gene expression profile indicative of earlier involution relative to unshaved mice. Once provided with enhanced capacity to dissipate body heat, shaved mice were likely to rear their young to independence faster than unshaved mothers.
|Number of pages||22|
|Journal||Journal of Comparative Physiology. B, Biochemical, Systemic, and Environmental Physiology|
|Early online date||18 Jan 2023|
|Publication status||Published - 1 Mar 2023|
We greatly benefited from discussing our work with Drs Torsten Stein, Wendy Woodward (who shared her raw data with us), and Sally Ward. We thank Catherine Hambly and Peter Thomson for assistance with isotope analyses.
The study was funded by Biotechnology and Biological Sciences Research Council (BBSRC) grants BB/G009953/1, BB/P009875/1 and BB/J020029/1, awarded to JRS. EK was supported by BBSRC grants BB/C504794/1 and BB/R018812/1.
Data Availability StatementData availability The RNA-seq data generated for this study are available in the ArrayExpress repository (http://www.ebi.ac.uk/arrayexpress/) under accession number E-MTAB-11654. The R script is available from FT on request.
- Heat dissipation limit
- Milk production
- Milk synthesis-related genes
- Involution-related genes
- Mammary gland involution
- Mother-young conflict