ISOLATION OF SCID PRE-B CELLS THAT REARRANGE KAPPA-LIGHT CHAIN GENES - FORMATION OF NORMAL SIGNAL AND ABNORMAL CODING JOINS
ISOLATION OF SCID PRE-B CELLS THAT REARRANGE KAPPA-LIGHT CHAIN GENES - FORMATION OF NORMAL SIGNAL AND ABNORMAL CODING JOINS
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DOI：
10.1002/j.1460-2075.1989.tb03433.x
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发表时间：
1989-03-01
期刊：
影响因子：
11.4
通讯作者：
ALT, FW
中科院分区：
文献类型：
--
作者：
BLACKWELL, TK;MALYNN, BA;ALT, FW
Consistent with an ordered immunoglobulin (Ig) gene assembly process during precursor (pre-) B cell differentiation, we find that most Abelson murine leukemia virus (A-MuLV)-transformed pre-B cells derived from scid (severe combined immune deficient) mice actively form aberrant rearrangements of their Ig heavy chain locus but do not rearrange endogeneous .vkappa. light chain variable region gene segments. However, we have identified several scid A-MuLV tranformants that transcribe the germline Ig .vkappa. light chain constant region and actively rearrange the .vkappa. variable region gene locus. In one case progression to the stage of .vkappa. light chain gene rearrangement did not require expression of Ig .mu. heavy chains; furthermore, this progression could not be efficiently induced following expression of .mu. heavy chains from an introduced vector. As observed in pre-B cell lines from normal mice, attempted V.vkappa.-to-J.vkappa. rearrangements in scid transformants occur by inversion at least as frequently as by deletion. The inverted rearrangements result in retention of both products of the recombination event in the chromosome, thus allowing their examination. scid .vkappa. coding sequence joins are aberrant and analogous in structure to previously described scid heavy chain coding joins. In contrast, the recognition signals that flank involved coding segments frequently are joined precisely back-to-back in normal fashion. The scid VDJ recombinase defect therefore does not significant impair recognition of, site-specific cutting at, or juxtaposition and appropriate ligation of signal sequence. Our finding that the scid defect prevents formation of correct coding but not signal joins distinguishes these events mechanistically.
