The development of adultoid reproductives and brachypterous neotenic reproductives from the last instar nymphs in Reticulitermes labralis (Isoptera: Rhinotermitidae): a comparative study.
Secondary reproductives develop primarily from nymphs. However, they have been rarely studied; in particular, the development of adultoid reproductives (AR) with floppy wings is still unclear. In this study, the change in juvenile hormone (JH) levels, vitellogenin gene expression, and oogenesis during the development of AR and brachypterous neotenic reproductives (BN) from the last instar nymphs of Reticulitermes labralis are investigated and compared. The results showed that the AR derived from the last instar nymphs by molting, and they were more similar to neotenic reproductives in morphology. In addition, the paired AR were not able to survive in the absence of workers. In R. labralis, the process of the last instar nymphs developing into AR and BN took an increase in JH level as a starting point. The JH level of the last instar nymphs molting into BN was approximately 1.5-fold higher than that of the AR. Additionally, The JHIII level of BN peaked on day 5, and that of AR peaked on day 10, which induced the onset of vitellogenesis in BN and AR, respectively. After molting, the vitellogenin gene expression levels of both BN and AR initially increased and then declined, and the expression levels in the BN were significantly higher than those in the AR. In addition, the oocytes of BN matured earlier than those of the AR, and the number of eggs laid by the BN was higher than the number laid by the AR. Our results demonstrate that, in R. labralis, the last instar nymphs can develop into AR, which are significantly different from BN in their development.
Biology Department, College of Life Sciences, Northwest University, Xi'an, China sxhnwu@nwu.edu.cn.
Xiao Hong
XH
Su
Biology Department, College of Life Sciences, Northwest University, Xi'an, China.
Wei
W
Xue
Biology Department, College of Life Sciences, Northwest University, Xi'an, China.
He
H
Liu
Biology Department, College of Life Sciences, Northwest University, Xi'an, China.
Jiao Ling
JL
Chen
Biology Department, College of Life Sciences, Northwest University, Xi'an, China.
Xiao Jing
XJ
Zhang
Biology Department, College of Life Sciences, Northwest University, Xi'an, China.
Lian Xi
LX
Xing
Biology Department, College of Life Sciences, Northwest University, Xi'an, China.
Ming Hua
MH
Liu
D000818:Animals; D005260:Female; D020049:Isoptera / Q000254:growth & development / Q000502:physiology*; D007605:Juvenile Hormones / Q000378:metabolism*; D008297:Male; D018978:Molting; D009758:Nymph / Q000254:growth & development; D009865:Oocytes; D010058:Oviposition / Q000502:physiology; D012098:Reproduction / Q000502:physiology; D014818:Vitellogenesis / Q000502:physiology; D014819:Vitellogenins / Q000235:genetics; D014921:Wings, Animal / Q000254:growth & development / Q000502:physiology
D007605:Juvenile Hormones; D014819:Vitellogenins
juvenile hormone; quantitative PCR; secondary reproductive; termite; vitellogenin gene expression