The immunoglobulin lambda variable light-chain region in primates has been shaped by multiple, independent, small-scale and large-scale insertion/deletion events.
We analyzed genomes of nonhuman primates to determine the ancestral state of a 9.1-kb insertion/deletion polymorphism, located on human chromosome 22. The 9.1-kb+ allele was found in 16 chimpanzees, 3 bonobos, and 2 Bornean orangutans; however, 9 chimpanzees and 6 Sumatran orangutans showed neither the 9.1-kb+ nor the 9.1-kb- allele, but a novel allele, termed 9.1-kbnull. A clone from a chimpanzee BAC library carrying the 9.1-kbnull allele was sequenced: the BAC DNA aligns with the human chromosome 22 reference sequence except for a 75-kb region, suggesting that the 9.1-kbnull allele originated from a deletion. Furthermore, the 9.1-kb+ chromosomes of chimpanzees and bonobos contain a 1030-nucleotide sequence, absent in humans, that may result from a retro-transposition insertion in their common ancestor. Our results provide additional evidence that human chromosome 22 has undergone multiple small-scale and large-scale insertions and deletions since sharing a common ancestor with other primates.
Coriell Institute for Medical Research, Camden, NJ 08103, USA.
Renato
R
Robledo
Patrick
P
Bender
Jay
J
Leonard
Baoli
B
Zhu
Kazutoyo
K
Osoegawa
Pieter
P
de Jong
Xi
X
Xu
Ziyun
Z
Yao
Bruce
B
Roe
D000818:Animals; D002892:Chromosomes, Human, Pair 22 / Q000235:genetics; D017353:Gene Deletion; D006801:Humans; D007147:Immunoglobulin Light Chains / Q000235:genetics*; D007135:Immunoglobulin Variable Region / Q000235:genetics*; D007146:Immunoglobulin lambda-Chains / Q000235:genetics*; D017404:In Situ Hybridization, Fluorescence; D016133:Polymerase Chain Reaction; D011323:Primates / Q000235:genetics*
D007147:Immunoglobulin Light Chains; D007135:Immunoglobulin Variable Region; D007146:Immunoglobulin lambda-Chains