DISTRIBUTION OF ENDOGENOUS CHICKEN RETROVIRUS SEQUENCES IN THE DNA OF GALLIFORM BIRDS DOES NOT COINCIDE WITH AVIAN PHYLOGENETIC-RELATIONSHIPS
DISTRIBUTION OF ENDOGENOUS CHICKEN RETROVIRUS SEQUENCES IN THE DNA OF GALLIFORM BIRDS DOES NOT COINCIDE WITH AVIAN PHYLOGENETIC-RELATIONSHIPS
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DOI：
10.1016/0092-8674(79)90270-8
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发表时间：
1979-01-01
期刊：
影响因子：
64.5
通讯作者：
STEHELIN, D
中科院分区：
文献类型：
--
作者：
FRISBY, DP;WEISS, RA;STEHELIN, D
这种鸡是家养的红少头鸡(Gallus Gallus)，属于雀形目的野鸡科(Phasianidae)。家鸡携带内源性逆转录病毒RAV[ROS相关病毒]-O的基因组，作为DNA序列整合到通过生殖系传递的宿主染色体中。我们研究了红毛鸡和其他近缘种，以及更远缘的山鸡和鹌鹑的DNA中RAV-O相关序列的存在和分布。对与RAV-O同源的DNA序列进行液体分子杂交和限制性内切酶片段电泳法分析。禽类DNA中RAV-O相关序列的存在与系统发育关系无关。在严格的液体杂交条件下，与RAV-O c[互补]DNA高度同源的DNA序列仅在家鸡及其系统发育祖先红雏鸡的基因组中检测到(同源性为80%)。另有2个种的DNA。与RAV-O基因同源性为10%的序列包括：高丽鸡(G.sonnerati，Sonnerat‘’S)和变异鸡(G.varus，Green Junglefowl)；在允许错配的条件下，环颈鸡DNA与RAV-O基因的杂交率高达50%，与鹌鹑DNA的杂交率达24%，而与松花鸡、S和青少年鸡的杂交程度并未明显增加。限制性内切酶分析表明，在红雏鸡和家鸡中都有与鸡反转录病毒基因杂交的DNA片段，而在2只黄羽鸡种的DNA中也有多个片段。在Sonnerat‘’S、Ceylonans和Green Junglefings、另外2个山鸡属(Physolophus和Lopura)和1个鹌鹑属(Coturnix)的DNA中没有发现与鸡反转录病毒相关的片段。因此，与家鸡亲缘关系较近的3种雏鸡的DNA缺乏RAV-O序列，而与其亲缘关系较远的Phasianus spp.显示出显著的同源性。这些结果表明，在姬蜂科的进化过程中，RAV-O相关序列并没有与正常宿主基因一起分化。虽然到目前为止所研究的所有家鸡和红色少年鸡的RAV-O序列都是内源性的，但似乎RAV-O基因组在物种形成之后但在驯化之前相对较新地被引入到鸡胚系中，并且独立于在Phasianus属成员中发现的相关序列。
The chicken is a domesticated form of Red Junglefowl (Gallus gallus), which belongs to the pheasant family (Phasianidae) within the order Galliformes. Domestic chickens carry the genome of the endogenous retrovirus RAV[Rous associated virus]-O as DNA sequences integrated into host chromosomes transmitted through the germ line. We have examined the presence and distribution of RAV-O-related sequences in the DNA of Red Junglefowl and other closely related species of Junglefowl, and more distantly related pheasants and quail. DNA sequences homologous to RAV-O were analyzed by molecular hybridization in liquid and after electrophoresis of restriction endonuclease fragments. The presence of RAV-O-related sequences in avian DNA does not correlate with phylogenetic relationships. Under stringent conditions of hybridization in liquid, DNA sequences homologous to RAV-O c[complementary]DNA were detected at high levels (> 80% homology) only in the genomes of the domestic chicken and its phylogenetic ancestor, the Red Junglefowl (G. gallus). The DNA of 2 other spp. of Gallus (G. sonnerati, Sonnerat''s Junglefowl and G. varius, Green Junglefowl), of ring-necked pheasant and of Japanese quail contained sequences with < 10% homology to RAV-O cDNA. Under conditions permitting mismatching, ring-necked pheasant DNA hybridized up to 50% of the RAV-O cDNA, and quail DNA 24%, whereas the extent of hybridization to Sonnerat''s and Green Junglefowl DNA was not markedly increased. Analysis of restriction enzyme digests revealed several distinct fragments of DNA hybridizing to chick retrovirus cDNA in both Red Junglefowl and domestic chicken, and multiple fragments in DNA from 2 Phasianus spp. No fragments with sequences related to chicken retroviruses were found in digests of DNA prepared from Sonnerat''s, Ceylonese and Green Junglefowl, from 2 other pheasant genera (Chrysolophus and Lophura, or from 1 Quail genus (Coturnix). Thus, the DNA of 3 Junglefowl species closely related to G. gallus lacked RAV-O sequences while the DNA of more distantly related Phasianus spp. showed significant homology. These results show that RAV-O-related sequences did not diverge together with the normal host genes during the evolution of the Phasianidae. Although RAV-O sequences are endogenous in all domestic chickens and Red Junglefowl studied thus far, it appears that the RAV-O genome was introduced relatively recently into the germ line of G. gallus, following speciation but before domestication, and independently of the related sequences found in members of the genus Phasianus.