Conservation of delta-crystallin gene structure between ducks and chickens.
A cloned chicken delta-crystallin cDNA was used to identify two putative delta-crystallin genes in the duck by Southern blot hybridization. A DNA fragment containing most of one of these genes was isolated from a library made in bacteriophage lambda Charon 28A containing genomic DNA from 14-day-old embryonic ducks. Electron microscopy, partial gene sequencing, primer extension analysis using duck mRNA, and comparison with the well-characterized chicken delta-crystallin genes suggest that our cloned duck delta-crystallin gene, like the chicken delta-crystallin genes, is 8-10 kb long and contains 17 exons. Hybridization and sequencing data show great similarity between the homologous 5' untranslated and coding exons of the duck and chicken delta-crystallin genes. Overall, the homologous introns also appear to have approximately 30% sequence similarity, and have been subject to deletion/insertion events. Our partial characterization of duck delta-crystallin gene sequences suggests that this avian and reptilian crystallin family has been conserved during evolution, as have the other crystallin gene families that are expressed in the eye lens.
Piatigorsky
J
J
Laboratory of Molecular and Developmental Biology, National Eye Institute, Bethesda, Maryland 20892.
Norman
B
B
Jones
R E
RE
D000818:Animals; D001483:Base Sequence; D005075:Biological Evolution; D002645:Chickens / Q000235:genetics*; D003001:Cloning, Molecular; D003459:Crystallins / Q000235:genetics*; D004247:DNA / Q000648:ultrastructure; D004262:DNA Restriction Enzymes; D004372:Ducks / Q000235:genetics*; D004625:Embryo, Nonmammalian; D005796:Genes; D008099:Liver / Q000378:metabolism; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009693:Nucleic Acid Hybridization
D003459:Crystallins; D004247:DNA; D004262:DNA Restriction Enzymes