Mammary glands of Aly mice: developmental changes and lactation-related expression of specific proteins, alpha-casein, GLyCAM-1 and MAdCAM-1.

Abstract

(1) Aly mouse is an autosomal recessive mutant mouse that lacks lymph nodes and Peyer's patches. Defects of mammary glands might explain why these mice fail to nurture their pups. (2) Expressions of glycosylation-dependent cell adhesion molecule 1 (GlyCAM-1) and mucosal addressin cell adhesion molecule-1 (MAdCAM-1) in mammary glands of lactating mice have been suggested, but only scant information is available. The thickness and weight of mammary glands were measured directly. The expression of specific proteins, alpha-casein, GlyCAM-1, and MAdCAM-1 in mammary glands was detected by reverse transcription-polymerase chain reaction (RT-PCR). MAdCAM-1 expression was also confirmed by immunohistochemistry (IHC). Fat pads of mammary glands of homozygous (aly/aly) mice were small and weighed less than those of heterozygous (aly/+ ) mice. An increase in end-bud development was evident in aly/aly mice. During pregnancy, growth of the mammary gland and alveolar formation were noted in both groups. The expression of alpha-casein, GlyCAM-1 and MAdCAM-1 was detected in both groups of mice by RT-PCR from late-pregnancy. Immunohistochemically, MAdCAM-1 was noted in small vessels around the mammary globules. Our results demonstrated marked changes in the structure of the mammary glands of aly/aly mice. The expression of lactation-related proteins was detected during development, pregnancy, and lactation in both aly/aly and aly/+ mice.