SEX DIFFERENCES IN DEVELOPMENT
SEX DIFFERENCES IN DEVELOPMENT
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发育中的性别差异
DOI：
10.1111/j.1469-8749.1969.tb01424.x
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发表时间：
1969
影响因子：
3.8
通讯作者：
A. Robinson
中科院分区：
文献类型：
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作者：
A. Robinson
发育中的性别差异利用来自脑瘫合作研究的数据，辛格和他的同事4证明了从出生到四岁的身体，心理和神经发育的显著性别差异。在每一种情况下，男性都被证明处于不利地位。他们推测，这可能是由于新生儿生命中的性别差异，男性新生儿比女性有更多的异常。也许男性对出生创伤的抵抗力较低。这些研究结果与其他信息一致，表明从受孕开始，男性与女性相比处于不利地位。如此显著的是，尽管怀孕时的性别比例至少为110/100，出生时仍为106/100左右，但到50岁时，情况正好相反。毫无疑问，男性在子宫内和出生后都面临更大的风险。z* 虽然这种不同发病率和死亡率的原因尚不清楚，但至少有两种建议，它们都具有遗传意义：X染色体包含至少100个重要的基因，这些基因具有与生殖特别相关的功能以外的功能-例如，与血液凝固、对维生素D的敏感性、色盲等有关。与半合子男性相比，女性有两种剂量的这些基因，因此可能对发育的外部危害表现出更强的抵抗力。查尔兹已经列举了婴儿、儿童和成人中一些性连锁基因的证据。由于里昂的X染色体失活假说中固有的剂量补偿机制，这些抗性差异有时是轻微的，并且当生物体受到压力时，可能更有可能表现出来。似乎产前和围产期的经验可能使女性X染色体基因有效剂量的增加足以逐渐降低性别比。此外，男性的劣势可能不一定是致命的，但可能表现在性能下降。另一种可能性仍然是假设性的，即没有Y染色体基因的母亲倾向于对Y染色体产生的外来产物敏感，并试图排斥它们，从而为男性胚胎产生相对不健康的环境。这可能会在产前造成最小的神经损伤，从而导致男性行为障碍、大脑性麻痹、癫痫和智力迟钝的发病率增加。这一假说与已报道的男性怀孕使夫妇不太可能再生男性孩子的趋势相一致。当然，特定妇女变得敏感的能力会有所不同，这可能解释了为什么
SEX DIFFERENCES IN DEVELOPMENT UTILIZING data from the Collaborative Study of Cerebral Palsy, SINGER and his colleagues4 demonstrated significant sex differences in physical, psychological and neurological development from birth to four years of age. In each case, the male proved to be at a disadvantage. They postulate that this may have resulted from the significant differences between the sexes in neonatal life, male neonates having many more abnormalities than females. Perhaps males have a lower resistance to the trauma of birth. These findings agree with other information suggesting that males from the time of conception onwards are a disadvantaged group in comparison with females. So marked is this that although the sex ratio at conception is at least 110/100 and at birth is still about 106/100, by 50 years of age the reverse is true. Undoubtedly then, the male is at a greater risk, both in utero and after birth.z* Although the reasons for this differential morbidity and mortality are unknown, at least two suggestions have been made, both of them with genetic implications: The X-chromosome contains at least 100 important genes which have functions other than those specifically related to reproduction-e.g., related to clotting of blood, sensitivity to vitamin D, colour blindness, etc. The female has two doses of these genes, compared with the hemizygous male, and hence may reveal more resistance to external hazards of development. CHILDS' has enumerated evidence for this in infants, children and adults for some sex-linked genes. These differences in resistance are sometimes slight because of the dosage compensation mechanisms inherent in the X-chromosomal inactivation hypothesis of Lyon, and presumably are more likely to reveal themselves when the organism is stressed. It seems possible that the prenatal and perinatal experience may be such that the increased number of effective doses of X-chromosomal genes in the female may be sufficient to reduce the sex ratio progressively. In addition, the disadvantage of the male may not necessarily be lethal but may show itself in diminished performance. The other possibility, which is still hypothetical, involves the tendency for a mother with no Y-chromosomal genes to become sensitized to foreign products produced by Y-chromosomes and try to reject them, thus producing a relatively unhealthy environment for the male embryo. This might produce minimal neurological damage prenatally and thus account for the increased incidence of behavioural disorders, cerebral palsy, epilepsy and mental retardation in males. This hypothesis accords with the reported tendency of male pregnancies to render couples less likely to have further male ~h i ld ren .~ The ability of particular women to become sensitized would of course vary and may explain why the