Changes in ultrastructure of gonads and external morphology during aging in the parthenogenetic cladoceran Daphnia pulex

In this study, we recorded the growth, reproduction, and survival indicators of parthenogenetic D. pulex females to analyze the morphological changes that occur during senescence. We observed the growth and development of the parthenogenetic females on the 7th, 14th, 21 st, and 28th days by using scanning electron microscopy and ultrastructure of the gonads on the 7th, 14th and 21 st days with transmission electron microscopy. We found that body length and reproductive capacity in the parthenogenetic individuals first increased and then decreased with aging, and the survival rate decreased gradually. The depression of the brood pouch on the back of the parthenogenetic females implied a decline in gonadal function and gradual aging. During senescence, the number of lipid droplets in the gonads of the parthenogenetic females decreased, and the integrity of the mitochondria and peroxisome was destroyed. The results of our study revealed the morphological characteristics of senescence in D. pulex.Graphical abstractChanges in ultrastructure of gonads and external morphology during aging in the parthenogenetic cladoceran Daphnia pulex.We observed the growth and development of the parthenogenetic females with ages, as well as ultrastructure of the gonads. During senescence, the number of lipid droplets in the gonads decreased, and the integrity of the mitochondria and peroxisome was destroyed.
Source: Micron - Category: Biology Source Type: research