Parasitoid wasps are rapidly developing as a model for evolutionary biology. Here we present chromosomal genomes of two Anastatus wasps, A. japonicus and A. fulloi, and leverage these genomes to study two fundamental questions—genome size evolution and venom evolution. Anastatus shows a much larger genome than is known among other wasps, with unexpectedly recent bursts of LTR retrotransposons. Importantly, several genomic innovations, including Piwi gene family expansion, ubiquitous Piwi expression profiles, as well as transposable element-piRNA coevolution, have likely emerged for transposable element silencing to maintain genomic stability. Additionally, we show that the co-option evolution arose by expression shifts in the venom gland plays a dominant role in venom turnover. We also highlight the potential importance of non-venom genes that are coexpressed with venom genes during venom evolution. Our findings greatly advance the current understanding of genome size evolution and venom evolution, and these genomic resources will facilitate comparative genomics studies of insects in the future.

RT-qPCR remains a vital approach for molecular biology studies aimed at quantifying gene expression in a range of physiological or pathological settings. However, the use of appropriate reference genes is essential to attain meaningful RT-qPCR results. Anastatus japonicus Ashmead (Hymenoptera: Helicopteridae) is an important egg parasitoid wasp and natural enemy of fruit bugs and forest caterpillars. While recent transcriptomic studies have analyzed gene expression profiles in A. japonicus specimens, offering a robust foundation for functional research focused on this parasitoid, no validated A. japonicus reference genes have yet been established, hampering further research efforts. Accordingly, this study sought to address this issue by screening for the most stable internal reference genes in A. japonicus samples to permit reliable RT-qPCR analyses. The utility of eight candidate reference genes (ACTIN, TATA, GAPDH, TUB, RPL13, RPS6, EF1α, RPS3a) was assessed under four different conditions by comparing developmental stages (larvae, pupae, adults), tissues (abdomen, chest, head), sex (male or female adults), or diapause states (diapause induction for 25, 35, 45, or 55 days, or diapause termination). RefFinder was used to calculate gene stability based on the integration of four algorithms (BestKeeper, Normfinder, geNorm, and ΔCt method) to determine the optimal RT-qPCR reference gene. Based on this approach, RPS6 and RPL13 were found to be the most reliable reference genes when assessing different stages of development, while ACTIN and EF1α were optimal when comparing adults of different sexes, RPL13 and EF1α were optimal when analyzing different tissues, and TATA and ACTIN were optimal for different diapause states. These results provide a valuable foundation for future RT-qPCR analyses of A. japonicus gene expression and function under a range of experimental conditions.

Anastatus japonicus Ashmead is a widely used biological control agent against stink bugs that can be successfully reared using the large eggs of the Chinese silkworm. In this study, environmental factors responsible for the induction of diapause in A. japonicus were investigated on host eggs of the Chinese silkworm. A. japonicus exhibited a facultative, mature larval diapause within its host eggs. Second–third instar larva are the most sensitive stages to diapause stimuli. The accumulation of diapause stimuli during all the larval stages maximized the diapause response. A short photoperiod of 10L:14D and temperature of 17 °C led to the occurrence of the highest diapause response, while a long photoperiod (14L:10D) and low temperatures (11 and 14 °C) prevented the diapause. A specific exposure period was required to reach high diapause incidence. Diapausing mature larvae had a significantly higher survival rate after 180 days storage at 10 °C than that of nondiapausing mature larvae. Taken together, results suggest methods that could be exploited in the developmental regulation, field-release pretreatment technology, and long-term storage of A. japonicus.

Chinese silkworm (Antheraea pernyi) eggs are used as factitious hosts of Anastatus fulloi, and refrigeration of these eggs is essential for large-scale rearing of A. fulloi. We studied the effects of cold storage of A. pernyi eggs on egg quality and the fitness of A. fulloi reared on the eggs. Four cold storage treatments and two cold storage periods were assessed. The 0–3 °C refrigerator treatment was unsuitable for long-term (>70 days) storage. Cold storage at −5 °C and −18 °C increased the loss rate of A. pernyi eggs, but there was no significant difference between the control and 0–3 °C water bath treatment. The parasitism rate of A. fulloi was reduced when A. pernyi eggs were refrigerated for 6 or 12 months. There were no obvious differences in eclosion rate and percentage of females between control and eggs subjected to 6-month storage in 0–3 °C, −5 °C, and −18 °C water bath treatments. However, the eclosion rate and percentage of females decreased sharply when the storage period was 12 months. The overall eclosion rate of A. fulloi was reduced at the prolonged refrigeration time. Cold storage reduced host egg quality and their fitness suitability for A. fulloi. To minimize losses in the large-scale rearing of A. fulloi, A. pernyi eggs should be refrigerated in a 0–3 °C or −5 °C water bath treatment, and the storage period should not exceed 6 months.

Objectives Tooth loss, which usually leads to malnutrition, is common in the elderly. However, limited information is available regarding its association with sarcopenia. This study aimed to investigate the relationship between loss of occlusal pairs of tooth and sarcopenia. Design A cross-sectional retrospective study was performed. Setting The elderly who participated in the National Basic Public Health Project in the Maigaoqiao Community Medical Center in Nanjing, Jiangsu Province, China. Participants A total of 2850 individuals aged ≥60 years were enrolled. Measurements Sarcopenia was defined according to the criteria proposed by the Asian Working Group for Sarcopenia. A trained dentist assessed oral health status and counted the number of present teeth. Logistic regression analyses were performed to evaluate the association between the loss of occlusal pairs and sarcopenia. Results The prevalence of sarcopenia was 7.1% (201/2850). Univariate logistic regression analysis showed that loss of occlusal pairs was associated with sarcopenia [anterior occlusal pairs (AOPs): odd ratio (OR) = 1.292, 95% confidence interval (CI) = 1.158–1.442; posterior occlusal pairs (POPs): OR = 1.147, 95% CI = 1.018–1.221]. Multivariate logistic regression analysis indicated that loss of POPs was still an independent risk for sarcopenia (OR = 1.108, 95% CI = 1.007–1.220) after adjustment for traditional confounders. Subgroup analysis showed that loss of POPs was more significantly linked to sarcopenia in those with advanced age (≥80years) (OR = 1.307, 95% CI = 1.116–1.532) and in females (OR = 1.165, 95%CI = 1.038–1.308). Compared to individuals with ≥5 occluding pairs of POPs, those with <5 occluding pairs of POPs had a higher incidence of sarcopenia. Conclusions Loss of POPs is associated with an increased risk of sarcopenia in the elderly in a Chinese population. Further research on the mechanism of the observed causal relationship is needed.