Evidence of a unique developmental mechanism specifying both wool follicle density and fibre size in sheep selected for single skin and fleece characters.
Evidence of a unique developmental mechanism specifying both wool follicle density and fibre size in sheep selected for single skin and fleece characters.
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独特发育机制的证据，指定了针对单皮和羊毛特征选择的绵羊的毛囊密度和纤维尺寸。
DOI：
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发表时间：
1989
期刊：
影响因子：
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通讯作者：
J. Lax
中科院分区：
文献类型：
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作者：
G. Moore;N. Jackson;J. Lax
皮肤和羊毛性状的特点是在四行的美利奴羊选择高，低纤维直径（D +/-）和主食长度（L +/-）从一个中等羊毛羊群。在20年的时间里，每一条生产线都朝着所需的方向发展，生产出由或粗或细的纤维和或长或短的羊毛斯台普斯组成的羊毛。然而，从这些程序中可能预期的羊毛生长量的变化被羊毛性状的变化所补偿。因此，预测的差异羊毛重量之间的高和低短纤维长度线减少了增加纤维卷曲频率在L-绵羊。同样，在D线的纤维直径引起的变化，导致在羊毛重量的影响较小相比，大（和反向）的影响毛囊数量。接近年底的选择制度，平均卵泡密度在D-羊的两倍，D+羊。进一步研究了卵泡群体中这种有趣的反应：对四个品系中卵泡密度和纤维直径之间关系的分析显示出高度显著的负线性相关。这种统计学关联的含义是，在胎儿生命期间皮肤中开始的毛囊数量对最终产生的羊毛纤维的大小有直接影响。得出的结论是，这两个功能必须在一个单一的发展机制的控制下。由于每个特征的表达在时间上是分开的，因此该机制必须在较早的事件期间被激活，即在卵泡启动阶段或之前。
Skin and fleece traits have been characterized in four lines of Merino sheep selected for high- and low-fibre diameter (D +/-) and staple length (L +/-) from a medium-woolled flock. Over a period of 20 years, each line responded in the desired direction, producing fleeces composed of thick or thin fibres and long or short wool staples. However, variations in the amounts of wool grown that might be expected from these procedures were compensated by changes in unselected characters. Thus a predicted difference in fleece weights between high and low staple length lines was reduced by an increase in fibre crimp frequency in L- sheep. Similarly, changes induced in fibre diameter in the D lines resulted in small effects on fleece weight in comparison to the large (and inverse) effects on follicle numbers. Towards the end of the selection regime, mean follicle density in D- sheep was twice that of D+ sheep. This intriguing response within the follicle population was examined further: an analysis of the relationship between follicle density and fibre diameter amongst the four lines revealed a highly significant, negative linear correlation. The implication of this statistical association is that the numbers of follicles initiated in skin during foetal life had a direct bearing on the sizes of wool fibres eventually produced. It was concluded that both features must be under the control of a single developmental mechanism. Since the expression of each of the characters is separated in time, the mechanism must be activated during the earlier event, i.e. at or before the phase of follicle initiation.