ISSN:
1617-4623
Keywords:
Heliothis interspecific matings
;
Male sterility
;
Sperm mitochondria
;
Mitochondrial transcripts
;
RNA metabolism
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
Notes:
Summary Interspecific matings between Heliothis virescens males and H. subflexa females result in the production of progeny normal in all respects except that the males are sterile. Recurrent backcrossing of fertile females to H. virescens males perpetuates testis dysfunction in these lines. Although the basis of this phenomenon is unknown, characteristic degenerative abnormalities in sperm mitochondria from backcross males suggest that the normal function of this organelle is disrupted. In order to test this notion, mitochondrial gene sequences have been isolated from a cDNA library constructed from H. virescens testis poly (A)+ RNA, aligned on the mitochondrial DNA physical map, and assigned genetic designations based upon their homology with sequenced mouse mitochondrial DNA restriction fragments. Hybridizations of these DNA sequences to RNA molecules from H. virescens and backcross testes revealed two major differences between the two lines: (1) the steadystate levels of mitochondrial transcripts from backcross testes were reduced approximately 3-fold relative to H. virescens; and (2) transcripts encoding mitochondrial proteins were not polyadenylated in backcross testes. Neither of these abnormalities appeared in mitochondrial transcripts from other tissues in backcross moths. These findings suggest that abnormal mitochondrial RNA metabolism is either a direct cause, or a manifestation of, the mechanism of sterility in backcross males.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00422070
