一只雌軍艦鳥在一群雄軍艦鳥的上空盤旋,，后者會(huì)立即膨脹起它們像紅氣球一樣的喉囊，借以展示自己的“男子氣”,，而這只雌軍艦鳥最終也會(huì)在一只最大,、最紅的“喉囊”邊落下腳來，并且陪伴在它的身邊,。
白腹軍艦鳥
但是這種大小與雞相仿的海鳥卻可能會(huì)突然甩了自己未來的伴侶,，前提是雄鳥聞起來與自己太過相似。
通過分析夏威夷種群的軍艦鳥的基因,，研究人員發(fā)現(xiàn),，雌軍艦鳥更喜歡與那些攜帶了一組名為主要組織相容性復(fù)合（MHC）標(biāo)記物的蛋白質(zhì)的雄軍艦鳥交配，后者從遺傳學(xué)角度來說與前者差異很大,，而不論這兩只“愛情鳥”是否是親戚,。
魚類和哺乳動(dòng)物似乎都能夠通過嗅覺區(qū)分不同的MHC蛋白質(zhì)，因此鳥類可能也會(huì)這樣做,，研究人員在5月24日出版的英國《皇家學(xué)會(huì)學(xué)報(bào)B》報(bào)告了這一研究成果,。
研究人員推測，由于MHC蛋白質(zhì)與免疫響應(yīng)有關(guān),，因此來自父母雙方的不同排列的蛋白質(zhì)將有助于后代避免更多類型的病原體的侵襲,，這可比一個(gè)漂亮的大喉囊重要得多。
軍艦鳥是一種大型熱帶海鳥,，全世界目前已知的有5種,，主要生活在太平洋、印度洋的熱帶地區(qū),。其捕食時(shí)的飛行時(shí)速可達(dá)400公里左右,，是世界上飛得最快的鳥之一。軍艦鳥還會(huì)通過騷擾其他帶著獵物歸來的海鳥獲得食物,。通過對(duì)其他正在飛行的鳥兒進(jìn)行干擾,，它們經(jīng)常會(huì)得到從其他海鳥嘴里掉落下來的食物。（生物谷Bioon.com）
生物谷推薦原文：
Proceedings of the Royal Society B: Biological Sciences DOI： 10.1098/rspb.2011.0562
Sequence-based evidence for major histocompatibility complex-disassortative mating in a colonial seabird
Juola, Frans A.; Dearborn, Donald C.
The major histocompatibility complex (MHC) is a polymorphic gene family associated with immune defence, and it can play arole in mate choice. Under the genetic compatibility hypothesis, females choose mates that differ genetically from their ownMHC genotypes, avoiding inbreeding and/or enhancing the immunocompetence of their offspring. We tested this hypothesis ofdisassortative mating based on MHC genotypes in a population of great frigatebirds (Fregata minor) by sequencing the second exon of MHC class II B. Extensive haploid cloning yielded two to four alleles per individual, suggestingthe amplification of two genes. MHC similarity between mates was not significantly different between pairs that did (n = 4) or did not (n = 42) exhibit extra-pair paternity. Comparing all 46 mated pairs to a distribution based on randomized re-pairings, we observedthe following (i): no evidence for mate choice based on maximal or intermediate levels of MHC allele sharing (ii), significantlydisassortative mating based on similarity of MHC amino acid sequences, and (iii) no evidence for mate choice based on microsatellitealleles, as measured by either allele sharing or similarity in allele size. This suggests that females choose mates that differgenetically from themselves at MHC loci, but not as an inbreeding-avoidance mechanism.
