異型合子優勢假說(heterozygosity advantage hypothesis)認為異型合子 (heterozygous)個體比同型合子個體有較高的適存性(fitness)。因此，天擇傾向最大化個體的異型合子歧異度。為驗證異型合子優勢假說，已有大量的研究針對生存能力、配對行為、繁殖成功率及疾病的抵抗能力等適存性特徵與個體的異型合子歧異度相關性進行探討，但大多數的研究都以成體的適存性特徵為研究主題。本實驗則於2007及08年3月至7月中旬以台灣中部青背山雀(Parus monticolus) 幼鳥為研究題材，以18組微衛星體(microsatellite)基因座估算個體的異型合子歧異度(以內在近親指數internal relatedness，IR表示)，以複迴歸控制巢及巢中雛數效應後，檢測幼鳥的異型合子歧異度與幼鳥孵化後的第3、11日齡體重、跗趾長及免疫力的相關性。結果顯示幼鳥內在近親指數與幼鳥免疫力(p=0.010) 呈現顯著的負相關，且Titgata89基因座中異型合子個體的第3日齡體重卻比同型合子個體輕(p = 0.0001)。此研究清楚的呈現異型合子歧異度與幼鳥適存性相關之形態特徵及生理特徵間的相關性，並推測可能受整體效應及局部效應的影響。另外，異型合子歧異度與幼鳥形態特徵間相關的現象，隨著幼鳥發展階段改變，在幼鳥體重發育趨於穩定時，異型合子歧異度與形態特徵的相關性消失，此項結果可為前人研究無法發現個體的異型合子
歧異度與成體形態特徵間相關性提供可能的解釋。

Heterozygosity advantage refers heterozygous individual having higher fitness than homozygous ones, i.e. natural selection may favor individuals with maximum genetic heterozygosity. Association between neutral genetic heterozygosity of an individual and its fitness components, such as survival and fecundity, are well established, but the relationship between heterozygosity and morphological traits of nestlings has been little studied. Here, I measured 99 green-backed tit (Parus monticolus) nestlings’ body mass and tarsus length on the 3rd and 11th day since hatching, and immune response. I then regressed these factors on individual heterozygosity index: individual’s internal relatedness (IR), as estimated from 18 microsatellite loci. The result obtained by multiple linear regression after controlling for nest and brood size shows significant negative correlation between immunocompetence and IR (p=0.010) , and positive local effect of IR at locus Titgata89 on body mass on the 3rd day of hatching (p=0.0001). This study clearly reveals heterozygosity fitness correlations in terms of both general effect and local effect. Furthermore, I found that correlations between heterozygosity and body mass during early developmental period disappear in later period; this may provide explanation for the lack of correlation between adult heterozygosity and morphological traits.

Allison, A. C. 1954. Protection afforded by sickle-cell trait against subtertian malarial infection. British Medical Journal, 1, 290 – 294.
Allan, J. B. et al., 2000. Molecular methods in ecology. Blackwell Science.
Amos, W., Wilmer, J. W., Fullard, K., Burg, T. M., Croxall, J. P., Bloch, D., Coulson, T. The influence of parental relatedness on reproductive success. Proceedings of the Roysal Society B: Biological Sciences, 268, 2021-2027.
Cichon, M. and Dubiec, A. 2005. Cell-mediated immunity predicts the probability of local recruitment in nestling blue tits. Journal of Evolutionary Biology, 18, 962-966.
Clotfelter, E. D., Whittingham L. A. and Peter, O. D. 2000. Laying order, hatching asynchrony and nestling body mass in tree swallows Tachycineta bicolor. Journal of Avian Biology, 31, 329-334.
Coltman, D. W. and Slate, J. 2003. Microsatellite measures of inbreeding: a meta-analysis. Evolution, 57, 971-983.
Conner, R. N., Saenz, D., Schaefer, R. R., McCormick, J. R., Rudolph, D. C. and Burt, D. B. 2005. Rainfall, El Niño, and reproduction of red-cockaded woodpeckers. Southeastern Naturalist, 4, 347-354.
Coulson, T. N., Pemberton, J. M., Albon, S. D., Beaumont, M., Marshall, T. C., Slate, J., Guinness, F. E. and Clutton-Brock, T. H. 1998. Microsatellites reveal heterosis in red deer. Proceedings of the Roysal Society, London series B, 265, 489-495.
Crow, J. F. 1948. Alternative hypotheses of hybrid vigor. Genetics, 33, 477-487.
David, P. 1998. Heterozygosity-fitness correlations: new perspectives on old problems. Heredity, 80, 531-537.
DeRose, M. A. and Roff, D. A. 1999. A comparison of inbreeding depression in life-history and morphological traits in animals. Evolution, 53, 1288-1292.
Foerster, K., Delhey, K., Johnsen, A., Lifjeld, J. T. and Kempenaers, B. 2003. Females increase offspring heterozygosity and fitness through extra-pair matings. Nature, 425, 714-717.
Fridolfsson, A. and Ellegren, H. 1999. A simple and universal method for molecular sexing of non-ratite birds. Journal of Avian Biology, 30, 116-121.
Frommen, J. G. and Bakker, T. C. M. 2006. Inbreeding avoidance through non-random mating in sticklebacks. Biology Letter, 2, 232-235.
Futuyma, D.J. 2005. Evolution. Sinauer Associates. Sunderland. Massachusetts.
Gage, M. J., Surridge, A. K., Tomkins, J. L., Green, E., Wiskin, L., Bell, D. J. and Hewitt, G. M. 2006. Reduced heterozygosity depresses sperm quality in wild rabbits, Oryctolagus cuniculus. Current Biology, 16, 612-617.
Garvin, J. C., Abroe, B., Pedersen, M. C., Dunn, P. O. and Whittingham, L. A. 2006. Immune response of nestling warblers varies with extra-pair paternity and temperature. Molecular Ecology, 15, 3833-3840.
Gemmell, N. J. and Akiyama, S. 1996. An efficient method for the extraction of DNA from vertebrate tissues. Trends in Genetics, 338-339.
Hansson, B. and Westerberg, L. 2002. On the correlation between heterozygosity and fitness in natural populations. Molecular Ecology, 11, 2467-2474.
Höglund, J., Piertney, S. B., Alatalo, R. V., Lindell, J. and Lundberg, A., Rintamäki, P. T. 2002. Inbreeding depression and male fitness in black grouse. Proceedings of the Royal Society B: Biological Sciences, 269, 711-715.
Hoffman, J. I., Forcada, J., Amos, W. 2006. No relationship between microsatellite variation and neonatal fitness in Antarctic fur seals, Arctocephalus gazella. Molecular Ecology, 15, 1955-2005.
Kawano, K. M. 2003. Isolation of polymorphic microsatellite markers in the great tit Parus major minor. Molecular Ecology Note, 3, 314-315.
Kempenaers, B., Verheyen, G. R. and Dhondt, A. A. 1997. Extrapair paternity in the blue tit Parus caeruleus: female choice, male characteristics, and offspring quality. Behavioral Ecology, 8, 481-492.
Kleven, O. and Lifjeld, J. T. 2004. Extrapair paternity and offspring immunocompetence in the reed bunting Emberiza schoeniclus. Animal Behaviour, 68, 283-289.
Kleven, O., Jacobsen, F., Izadnegahdar, R., Robertson, R. J. and Lifjeld, J. T. 2006. Male tail streamer length predicts fertilization success in the North American barn swallow Hirundo rustica erythrogaster. Behavioral Ecology and Sociobiology, 59, 412-418.
Kretzmann, M., Mentzer, L., DiGiovanni, R., Leslie, M. S. and Amato, G. 2006. Microsatellite diversity and fitness in stranded juvenile harp seals Phoca groenlandica. Journal of Heredity, 97, 6, 555-560.
Legge, S. 2002. Siblicide, starvation and nestling growth in the laughing kookaburra. Journal of Avian Biology, 33, 2, 159-166.
Lesbarreres, D., Primmer, C. R., Laurila, A. and Merila, J. 2005. Environmental and population dependency of genetic variability-fitness correlations in Rana temporaria. Molecular Ecology, 14, 311-323.
Lesbarrères, D., Schmeller, D. S., Primmer, C. R. and Merilä, J. 2007. Genetic variability predicts common frog Rana temporaria size at metamorphosis in the wild. Heredity, 99, 41-46.
Lessells, C. M. and Boag, P. T. 1987. Unrepeatable repeatabilities: a common mistake. Auk, 104, 116-121.
Lieutenant-Gosselin, M. and Bernatchez, L. 2006. Local heterozygosity - fitness correlations with global positive effects on fitness in. threespine stickleback. Evolution, 60, 1658-1668.
Lindstrom, J. 1999. Early development and fitness in birds and mammals. Trends in Ecology and Evolution, 14, 343-348.
Madsen, T. and Shine, R. 1992. Determinants of reproductive success in female adders Vipera berus. Oecologia, 92, 40–47.
Magrath, R.D. 1991. Nestling weight and juvenile survival in. the blackbird, Turdus merula. Journal of Animal Ecology, 60, 335–351.
Martin II, L. B., Han, P., Lewittes, J. R., Klasing, K. C. and Wikelski, M. 2006. Phytohemagglutinin-induced skin swelling in birds: histological support for a classic immunoecological technique. Functional Ecology, 20, 290-299.
Massemin, S., Korpimäki, E., Pöyri, V. and Zorn, T. 2002. Influence of hatching order on growth rate and resting metabolism of kestrel nestlings. Journal of Avian Biology, 33, 235-244.
Merila, J. and Svensson, E. 1997. Are fat reserves in migratory birds affected by condition in early life? Journal of Avian Biology, 28, 4, 279-286.
Merilä, J. and Sheldon, B. C. 1999. Genetic architecture of fitness and nonfitness traits: empirical patterns and development of ideas. Heredity, 83, 103-109.
Møller, A.P. and Saino, N. 2004. Immune response and survival. Oikos, 104, 299-304.
Moreno, J., Santiago, M., Juan, J. S., Elena, A., Judith, M. and Gustavo, T. 2005. Nestling cell-mediated immune response, body mass and hatching date as predictors of local recruitment in the pied flycatcher Ficedula hypoleuca. Journal of Avian Biology, 36, 251-260.
Murphy, M. T. 1985. Nestling eastern kingbird growth: effects of initial size and ambient temperature. Ecology, 66, 162-170.
Ortego, J., Cordero, P. J., Aparicio, J. M. and Calabuig, G. 2007. No relationship between individual genetic diversity and prevalence of avian malaria in a migratory kestrel. Molecular Ecology, 16, 4858-4866.
Østnes, J. E., Jenssen, B. M. and Bech, C. 2001. Growth and development of homeothermy in nestling european shags Phalacrocorax aristotelis. Auk, 118, 983-995.
Peles, J.D. and Merritt, J. F. 2005. Allozyme heterozygosity and metabolic rate in Blarina brevicauda. Pp 367–372, in Advances in the biology of shrews II (Merritt, J.F., Churchfield, S., Hutterer, R. and Sheftel, B.I. eds.) Special Publication, International Society of Shrew Biologists, No. 01: 1-468.
Pihlaja, M. 2006. Maternal effect in magpie. PhD thesis, University of. Jyväskylä, Finland.
Pitala, N. 2007. Causes and consequence of variation in nestling immune function. PhD thesis, University of Helsinki.
Pujolar, J. M., Maes, G. E., Vancoillie, C. and Volckaert, F. A. 2005. Growth rate correlates to individual heterozygosity in the European eel, Anguilla anguilla L. Evolution, 59, 189-199.
Queller, D. C. and Goodnight, K. F. 1989. Estimating relatedness using genetic markers. Evolution, 43, 258-275.
Raymond, M. and Rousset, F. 1995. GENEPOP (Version 1.2): Population genetics software for exact tests and ecumenicism. Journal of Heredity, 86, 248-249.
Remeŝ, V. and Martin, T. E. 2002. Environmental influences on the evolution of growth and developmental rates in passerines. Evolution, 56, 2505-2518.
Saino, N., Calza, S. and Møller, A.P. 1998. Effects of a dipterans ectoparasite on immune response and growth trade-offs in barn swallow, Hirundo rustica nestlings. Oikos, 81, 217-228.
Saladin, V., Bonfils, D., Binz, T. and Richner, H. 2003. Isolation and characterization of 16 microsatellite loci in the great tit Parus majo. Molecular Ecology Notes, 3, 520-522.
Schmeller, D. S., Schregel, J. and Veith, M. The importance of heterozygosity in a frog's life. Naturwissenschaften, 94, 360-366.
Schneider, S., Kueffer, J. M., Roessli, D. and Excoffier, L. 2002. Arlequin: a software for population genetics data analysis, version2.0. University of Geneva.
Seddon, N., Amos, W., Mulder, R. A. S. and Tobias, J. A. 2004. Male heterozygosity predicts territory size, song structure and reproductive success in a cooperatively breeding bird. Proceedings of the Royal Society B: Biology Science, 271, 1823-1829.
Shine, R., Olsson, M. M., Moore, I. T., Lemaster, M. P., Greene, M. and Mason, R. T. 2000. Body size enhances mating success in male garter snakes. Animal Behaviour, 59, F4-F11.
Slate, J., Kruuk, L. E., Marshall, T. C., Pemberton, J. M. and Clutton-Brock, T. H. 2000. Inbreeding depression influences lifetime breeding success in a wild population of red deer Cervus elaphus. Proceedings of the Royal Society B: Biology Science, 267, 1657-1662.
Soler, J. J., de Neve, L., Perez-Contreras, T., Soler, M. and Sorci, G. 2003. Trade-off between immunocompetence and growth in magpies: an experimental study. Proceedings of the Royal Society of London B: Biological Sciences, 270, 241–248.
Starck, J. M. and Richlef, R. E. 1998. Avian growth and development. New York: Oxford.
Tarvin, K. A., Webster, M. S., Tuttle, E. M. and Pruett-Jones, S. 2005. Genetic similarity of social mates predicts the level of extrapair paternity in splendid fairy-wrens. Animal Behaviour, 70, 4, 945-955.
Thomas, L., Sabine, S., Jorg, B., Thomas, G. and Jorg, T. E. 1999. Extra-pair paternity in great tits Parus major - a long term study. Behaviour, 136, 1157-1172.
Tinbergen, J. M. and Boerlojst, M. C. 1990. Nestling weight and survival in individual Great Tits Parus major. Journal of Avian Ecology, 59, 1113-1127.
Val Nolan, J. R and Ketterson, E. D. 1996. Current ornithology. New York: Spring Street.
王玫婷。2005。青背山雀的遺傳異配交配。碩士論文。國 立台灣師範大學。
姚正得。2005。奧萬大國家森林遊樂區利用鳥巢箱鳥類之生殖習性調查及監測。行政院農業委員會林務局。
羅文穗。2007。以微衛星體基因座及主要組織相容性複合體之異型合子度探討青背山雀之配對模式。碩士論文。國立台灣師範大學生命科學系。
蕭明堂。2006。關原地區青背山雀 Parus monitcolus 親鳥育雛食物分配之探討。碩士論文。國立台灣師範大學生命科學系。