LOCAL HETEROZYGOSITY-FITNESS CORRELATIONS WITH GLOBAL POSITIVE EFFECTS ON FITNESS IN THREESPINE STICKLEBACK

The complex interactions between genetic diversity and evolution have important implications in many biological areas including conservation, speciation, and mate choice. A common way to study these interactions is to look at heterozygosity-fitness correlations (HFCs). Until recently, HFCs based on noncoding markers were believed to result primarily from global inbreeding effects. However, accumulating theoretical and empirical evidence shows that HFCs may often result from genes being linked to the markers used (local effect). Moreover, local effect HFCs could differ from global inbreeding effects in their direction and occurrence. Consequently, the investigation of the structure and consequences of local HFCs is emerging as a new important goal in evolutionary biology. In this study of a wild threespine stickleback (Gasterosteus aculeatus) population, we first tested the presence of significant positive or negative local effects of heterozygosity at 30 microsatellites loci on five fitness components: survival, mating success, territoriality, length, and body condition. Then, we evaluated the direction and shape of total impact of local HFCs, and estimated the magnitude of the impacts on fitness using regression coefficients and selection differentials. We found that multilocus heterozygosity was not a reliable estimator of individual inbreeding coefficient, which supported the relevance of single-locus based analyses. Highly significant and temporally stable local HFCs were observed. These were mainly positive, but negative effects of heterozygosity were also found. Strong and opposite effects of heterozygosity are probably present in many populations, but may be blurred in HFC analyses looking for global effects only. In this population, both negative and positive HFCs are apparently driving mate preference by females, which is likely to contribute to the maintenance of both additive and nonadditive genetic variance.

[1]  E. Ranta,et al.  Do dominants have higher heterozygosity? Social status and genetic variation in brown trout, Salmo trutta , 2006, Behavioral Ecology and Sociobiology.

[2]  Z. Chen,et al.  Molecular marker genotypes, heterozygosity and genetic interactions explain heterosis in Arabidopsis thaliana , 2005, Heredity.

[3]  T. Pitcher,et al.  Genetic quality and sexual selection: an integrated framework for good genes and compatible genes , 2004, Molecular ecology.

[4]  L. Bernatchez,et al.  NONLINEAR EFFECTS OF FEMALE MATE CHOICE IN WILD THREESPINE STICKLEBACKS , 2004, Evolution; international journal of organic evolution.

[5]  F. Balloux,et al.  Does heterozygosity estimate inbreeding in real populations? , 2004, Molecular ecology.

[6]  G. Hill,et al.  Choosing mates: good genes versus genes that are a good fit. , 2004, Trends in ecology & evolution.

[7]  I. Boyd,et al.  Patterns of parental relatedness and pup survival in the grey seal (Halichoerus grypus) , 2004, Molecular ecology.

[8]  N. J. Ouborg,et al.  Introduction Strategies Put to the Test: Local Adaptation versus Heterosis , 2004 .

[9]  B. Grant,et al.  Neutral locus heterozygosity, inbreeding, and survival in Darwin's ground finches (Geospiza fortis and G. scandens) , 2004, Heredity.

[10]  L. Bernatchez,et al.  Offspring genetic diversity increases fitness of female Atlantic salmon (Salmo salar) , 2004, Behavioral Ecology and Sociobiology.

[11]  B. Grant,et al.  INBREEDING AND INTERBREEDING IN DARWIN'S FINCHES , 2003, Evolution; international journal of organic evolution.

[12]  M. Blows,et al.  EVOLUTION OF ADDITIVE AND NONADDITIVE GENETIC VARIANCE IN DEVELOPMENT TIME ALONG A CLINE IN DROSOPHILA SERRATA , 2003, Evolution; international journal of organic evolution.

[13]  J. Slate,et al.  MICROSATELLITE MEASURES OF INBREEDING: A META‐ANALYSIS , 2003, Evolution; international journal of organic evolution.

[14]  B. Hansson,et al.  On the correlation between heterozygosity and fitness in natural populations , 2002, Molecular ecology.

[15]  L. Keller,et al.  Inbreeding effects in wild populations. , 2002 .

[16]  J. Slate,et al.  Comparing molecular measures for detecting inbreeding depression , 2002 .

[17]  S. Kalinowski,et al.  INBREEDING DEPRESSION IN CONSERVATION BIOLOGY , 2000 .

[18]  T. C. Marshall,et al.  Inbreeding depression influences lifetime breeding success in a wild population of red deer (Cervus elaphus) , 2000, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[19]  Braithwaite,et al.  The paradox of the stickleback: different yet the same. , 1999, Trends in ecology & evolution.

[20]  J. Slate,et al.  MICROSATELLITE LOCI REVEAL SEX‐DEPENDENT RESPONSES TO INBREEDING AND OUTBREEDING IN RED DEER CALVES , 1999, Evolution; international journal of organic evolution.

[21]  D. Coltman,et al.  PARASITE‐MEDIATED SELECTION AGAINST INBRED SOAY SHEEP IN A FREE‐LIVING ISLAND POPULATON , 1999, Evolution; international journal of organic evolution.

[22]  D. Coltman,et al.  Birth weight and neonatal survival of harbour seal pups are positively correlated with genetic variation measured by microsatellites , 1998, Proceedings of the Royal Society of London. Series B: Biological Sciences.

[23]  P. David.  Heterozygosity–fitness correlations: new perspectives on old problems , 1998, Heredity.

[24]  I. Hanski,et al.  Inbreeding and extinction in a butterfly metapopulation , 1998, Nature.

[25]  M. Lynch,et al.  Mutation Accumulation and the Extinction of Small Populations , 1995, The American Naturalist.

[26]  G. J. Fitzgerald,et al.  Parental care tactics of three-spined sticklebacks living in a harsh environment , 1992 .

[27]  P. Borsa,et al.  Relationships between allozymic heterozygosity, body size, and survival to natural anoxic stress in the palourde Ruditapes decussatus L. (Bivalvia : Veneridae) , 1992 .

[28]  D. Roff,et al.  Quantitative genetics and fitness: lessons from Drosophila , 1987, Heredity.

[29]  F. James Rohlf,et al.  Biometry: The Principles and Practice of Statistics in Biological Research , 1969 .