A Microarray-Based Analysis Reveals that a Short Photoperiod Promotes Hair Growth in the Arbas Cashmere Goat.

Bin Liu,Jun Guo,Bayasihuliang Hao,Yurong Li,Cunfa Zhao,Dubala Wu,Fengqin Gao,Andrzej T Slominski

doi:10.1371/journal.pone.0147124

Abstract

Many animals exhibit different behaviors in different seasons. The photoperiod can have effects on migration, breeding, fur growth, and other processes. The cyclic growth of the fur and feathers of some species of mammals and birds, respectively, is stimulated by the photoperiod as a result of hormone-dependent regulation of the nervous system. To further examine this phenomenon, we evaluated the Arbas Cashmere goat (Capra hircus), a species that is often used in this type of research. The goats were exposed to an experimentally controlled short photoperiod to study the regulation of cyclic cashmere growth. Exposure to a short photoperiod extended the anagen phase of the Cashmere goat hair follicle to increase cashmere production. Assessments of tissue sections indicated that the short photoperiod significantly induced cashmere growth. This conclusion was supported by a comparison of the differences in gene expression between the short photoperiod and natural conditions using gene chip technology. Using the gene chip data, we identified genes that showed altered expression under the short photoperiod compared to natural conditions, and these genes were found to be involved in the biological processes of hair follicle growth, structural composition of the hair follicle, and the morphogenesis of the surrounding skin appendages. Knowledge about differences in the expression of these genes as well as their functions and periodic regulation patterns increases our understanding of Cashmere goat hair follicle growth. This study also provides preliminary data that may be useful for the development of an artificial method to improve cashmere production by controlling the light cycle, which has practical significance for livestock breeding.

Highlights

In Inner Mongolia, the Cashmere goat (Capra hircus) is important for its wool
Under the short photoperiod conditions, the Cashmere goat histology results showed that hair follicles have remarkable anagen morphological characteristics and are significantly thicker compared with the control group
Our results reveal that the short photoperiod induced differential VEGFR-1 expression in the hair follicles in skin during the anagen phase, which provides important insight that VEGFR-1 may participate in the reconstruction of periodic Cashmere goat hair follicles, a possibility that should be investigated further

Summary

Introduction

In Inner Mongolia, the Cashmere goat (Capra hircus) is important for its wool. Cashmere production depends primarily on the area and length of the cashmere fiber, which are determined by the number of secondary follicles and the hair growth cycle [2]. There is a large difference among the different varieties of Cashmere goat. Nutritional conditions typically affect cashmere production and quality, and the seasonal photoperiod induces a large increase in cashmere production [3]. This seasonal phenomenon depends on the photoperiod-dependent regulation of the endocrine and the nervous systems by illumination, which can release a variety of hormones. Previous studies have shown that melatonin (MEL) [4,5,6], prolactin (PRL), growth hormone, insulin-like growth factor 1 (IGF-1), and thyroid hormone directly affect cashmere growth in Australian goats [7,8,9,10,11,12]

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