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Monday, October 13, 2014

Telegony, Virginity and Damaged Goods

Telegony was a once discredited theory--even termed a superstition--that a woman's first sexual partner could pass traits on to subsequent children of the woman, even if the children were sired by a different person. Apparently the science was not settled. An abstract from  Reprod Domest Anim. 2011 Apr;46(2):338-43.
Telegony is the belief that the sire first mated to a female will have an influence upon some of that female's later offspring by another male. Although the reality of telegony was acknowledged by such authorities as Darwin, Spencer, Romanes and many experienced breeders, it has been met with scepticism because of Weismann's unfavourable comments and negative results obtained in several test experiments. In this article, alleged cases of telegony are provided. A search of the literature of cell biology and biochemistry reveals several plausible mechanisms that may form the basis for telegony. These involve the penetration of spermatozoa into the somatic tissues of the female genital tract, the incorporation of the DNA released by spermatozoa into maternal somatic cells, the presence of foetal DNA in maternal blood, as well as sperm RNA-mediated non-Mendelian inheritance of epigenetic changes.
An abstract from Gene. 2013 Jul 25;524(2):414-6:
Telegony is a discredited genetic phenomenon that a previous male may influence the characteristics of offspring subsequently borne by the same female to another male. Although its reality was acknowledged by such authorities as Charles Darwin and Herbert Spencer, it has been met with skepticism because of a lack of understanding of the theoretical basis for telegony. With the discovery of fetal genes in mother's blood, the penetration of somatic cells by sperm, and the ability of RNA to program genome rearrangement, mechanisms might exist for telegony.
An abstract from Ecology Letters on September 30, 2014:
Newly discovered non-genetic mechanisms break the link between genes and inheritance, thereby also raising the possibility that previous mating partners could influence traits in offspring sired by subsequent males that mate with the same female (‘telegony’). In the fly Telostylinus angusticollis, males transmit their environmentally acquired condition via paternal effects on offspring body size. We manipulated male condition, and mated females to two males in high or low condition in a fully crossed design. Although the second male sired a large majority of offspring, offspring body size was influenced by the condition of the first male. This effect was not observed when females were exposed to the first male without mating, implicating semen-mediated effects rather than female differential allocation based on pre-mating assessment of male quality. Our results reveal a novel type of transgenerational effect with potential implications for the evolution of reproductive strategies.
Or, as The Telegraph reports the findings:
The idea that the physical traits of previous sexual partners could be passed on to future children was hypothesised by Aristotle and formed part of the reason that kings were banned from marrying divorcees. 
But the birth of genetics dismissed ‘telegony’ as a superstition which had no basis in science. 
Now, however, an intriguing new study suggests children may resemble a mother’s previous sexual partner after all. 
Scientists at the University of New South Wales discovered that, for fruit flies at least, the size of the young was determined by the size of the first male the mother mated with, rather than the second male that sired the offspring. 
It is the first time that telegony has been proved in the animal kingdom. 
The researchers propose that the effect is due to molecules in the semen of the first mate being absorbed by the female's immature eggs where they influence future offspring.
(See also the International Business Times and the Daily Mail).

 (H/t Alpha Game)

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