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The strong links between Epstein-Barr virus (EBV) and endemic Burkitt's lymphoma suggest that the virus activates the complicated chain of events that cause the tumor (1,2). EBV was recently implicated [...]

Chromosomal rearrangements that create gene fusions are common features of human tumors. The prevailing view is that the resultant chimeric transcripts and proteins are abnormal, tumor-specific products that provide tumor cells with a growth and/or survival advantage. We show that normal endometrial stromal cells contain a specific chimeric RNA joining 5' exons of the JAZF1 gene on chromosome 7p15 to 3' exons of the Polycomb group gene JJAZ1/SUZ12 on chromosome 17q11 and that this RNA is translated into JAZF1-JJAZ1, a protein with anti-apoptotic activity. The JAZF1-JJAZ1 RNA appears to arise from physiologically regulated trans-splicing between precursor messenger RNAs for JAZF1 and JJAZ1. The chimeric RNA and protein are identical to those produced from a gene fusion found in human endometrial stromal tumors. These observations suggest that certain gene fusions may be pro-neoplastic owing to constitutive expression of chimeric gene products normally generated by trans-splicing of RNAs in developing tissues.

In sum, it appears that legal abortion depressed overall fertility, but particularly illegitimate fertility, by giving women an opportunity to terminate their pregnancies when other means of birth control either had not been used or had failed. If legalized abortion had not been available, an estimated additional 39,000 illegitimate babies and 28,000 legitimate babies would have been born in 1971 in the United States. While this makes up a small part of total births (3,500,000), the illegitimate births prevented represent almost onetenth of all out-of-wedlock children born in the country in that year. In addition to preventing these births the legalization of abortion appears to have reduced the incidence of pregnancy-related marriages and thereby may have helped to limit subsequent marital disruption. Finally, legal abortion prevented large numbers of illegal abortions from occurring. Our data indicate that well over half-most likely between two-thirds and three-fourths-of all legal abortions in the United States in 1971 were replacements for illegal abortions. Further declines in illegitimate birth rates for the country as a whole will depend, in considerable part, on the extent to which legal abortion becomes more readily available and more widely used. Theoretically, greater use of efficient contraception could also cause illegitimate fertility to decline. But there are many reasons why women do not use efficient contraception even when they know about it and have access to the materials (25). Even though the use of abortion throughout the nation is now legalized by the Supreme Court decision, this does not necessarily mean that services will in fact be everywhere more readily available. Our interstate analysis suggests that should the liberalization of abortion laws be reversed, not only would there be an upturn in illegal abortions and pregnancy-related marriages, but also a marked rise in illegitimacy, particularly among women who do not have the means to obtain an illegal abortion.

Joining of V-, D-, and J-region gene segments during DNA rearrangements within all antigen receptor genes involves recognition of the same highly conserved heptamernonamer sequences flanking each segment. In order to investigate the possibility that recognition of these conserved sequences may sometimes permit intergenic joining of segments among different antigen receptor genes, DNA of normal human lymphoid tissues was examined by polymerase chain reaction amplification for the presence of chimeric gamma-delta T cell receptor gene rearrangements. These studies detected V gamma-(D delta)-J delta and V delta-(D delta)-J gamma rearrangements in thymus, peripheral blood, and tonsil. Analysis of thymus RNA indicated that many of these rearrangements are expressed as V gamma-(D delta)-J delta-C delta and V delta-(D delta)-J gamma-C gamma transcripts. Most transcripts (19 of 20 complementary DNA clones studied) are appropriately spliced and show correct open translational reading frames across the V-(D)-J junctions. Thus, chimeric antigen receptor genes are generated in a subset of normal lymphoid cells, probably as a result of chromosomal translocations, and such genes may possibly contribute to increased diversity within the antigen receptor repertoire.