Earwigs raised without parents demonstrate limited maternal care of their own offspring

http://www.eurekalert.org/pub_releases/2015-11/jgum-erw111615.php

Public Release: 16-Nov-2015
Earwigs raised without parents demonstrate limited maternal care of their own offspring
Lack of brood care has a short-term advantage but is disadvantageous in long-term transgenerational effects
Johannes Gutenberg Universitaet Mainz

For young animals depending on maternal care for survival, the loss of parents often leads to serious consequences and even death. The effect of the loss of parents among animals that could, in principle, survive without maternal care has now been researched by scientists at Johannes Gutenberg University Mainz (JGU) using the example of the earwig - with surprising results. Contrary to expectations, earwigs raised without mothers became even larger as mature adults compared to those that were raised by their mothers. But when they produced their own offspring, they were less liable to care for them. Astonishingly, the loss of the mother had transgenerational effects which became apparent in the characteristics of the offspring of the orphaned animals. In other words, the loss of the mother in the case of earwigs was associated with a short-term advantage but with long-term cost.

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The researchers had to use a complex sequence of experiments in order to be able to investigate the longer-term, transgenerational effects of a lack of brood care. In the end, this revealed that the attributes of the offspring raised without mothers were affected. For example, foster mothers defended juveniles of orphaned females less well than the offspring of animals that had themselves been exposed to brood care. The long-term and transgenerational effects are thus significantly more negative than the direct effects of a lack of maternal care. "It was previously assumed that the ramifications associated with brood care were not inherited, but now we see that there is, in fact, a - possibly epigenetic - transfer," concluded Kramer.

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