Lisa A, Astolfi P, Degioanni A, Di Pasquale C, Zei G
Istituto di Genetica Biochimica ed Evoluzionistica del Consiglio Nazionale delle Ricerche (CNR), Pavia, Italy.
Hum Biol. 1994 Aug;66(4):683-98.
Women's fertility, gathered from the 1961 Italian population census, and estimates of heterozygote frequencies for thalassemia and G6PD deficiency (Siniscalco et al. 1961, 1966) in 52 Sardinian villages were examined to study at the population level the mechanisms that have maintained the stability of these polymorphisms over long periods. Sardinian villages were classified according to low or high frequency of heterozygotes, and the reproductive behavior of the women living in these areas was analyzed. A high mean number of children per woman and a low percentage of women without children with a high heterozygote frequency was demonstrated. The observed differential fertility and sterility were interpreted as being the result of different numeric ratios within each area between normal homozygous and heterozygous women, who were less and more resistant, respectively, to malarial infection, according to Haldane's theory. The effect of differing degrees of malaria on fertility rates has been demonstrated previously (Zei et al. 1990). To account for the effect of the genetic and epidemiological composition of an area on reproductive behavior, we classified data on women's fertility and sterility by heterozygote frequency level and malarial morbidity level. A combined and direct effect of inherited and acquired immunities on fertility and sterility rates was shown. The level of endemicity in an area may contribute to decreasing or increasing fitness, which is already influenced by the stable balanced polymorphisms.
我们研究了从1961年意大利人口普查中收集的女性生育力数据，以及52个撒丁岛村庄地中海贫血和葡萄糖-6-磷酸脱氢酶（G6PD）缺乏症杂合子频率的估计值（西尼斯卡尔科等人，1961年、1966年），以便在人群层面研究长期维持这些多态性稳定性的机制。根据杂合子的低频或高频对撒丁岛村庄进行分类，并分析了生活在这些地区的女性的生殖行为。结果表明，每个女性的平均子女数较高，且在杂合子频率高的地区，无子女女性的比例较低。根据霍尔丹的理论，观察到的生育力和不育率差异被解释为每个地区正常纯合子和杂合子女性数量比例不同的结果，她们分别对疟疾感染的抵抗力较低和较高。先前已经证明了不同程度的疟疾对生育率的影响（泽伊等人，1990年）。为了解释一个地区的遗传和流行病学构成对生殖行为的影响，我们按杂合子频率水平和疟疾发病率水平对女性生育力和不育率数据进行了分类。结果显示了遗传免疫和后天免疫对生育力和不育率的综合直接影响。一个地区的地方病流行程度可能有助于降低或提高适合度，而适合度已经受到稳定平衡多态性的影响。
