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Studies have identified that mating induces a series of physiological changes in animals. In this period, males tending to invest more energy, immune peptides, and other substances to reduce the cost of living for females. This results in lower survival rates in later life than females. Meanwhile, both males and females shorten lifespans due to reproduction. However, the reasons why termites' queens and kings are both extremely long-lived and highly fecund are unclear. Therefore, this study aimed to examine the effects of mating on the expression of immune and DNA repair genes for lifespan extension in termite queens and kings. Here, we reported that mated queens show relatively higher expression of immune genes (phenoloxidase, denfensin, termicin, transferrin), antioxidant genes (CAT, SOD), detoxification genes (GST, CYP450) than virgin queens in the Reticulitermes chinensis. In addition, mated kings also highly expressed these genes, except for termicin, transferrin, GST, and CYP450. After mating, both queens and kings significantly upregulated the expression of DNA repair genes (MLH1, BRCA1, XRCC3, RAD54-like). Mismatch repair genes (MMR) MSH2, MSH4, MSH6 were considerably increased in mated queens, while MSH4, MSH5, MSH6 were upregulated in mated kings. Our results suggest that mating increases the expression of immune and DNA repair genes in the termite queens and kings, and thus possibly improving their survival during reproductive span due to the omnipresent pathogens.

Worldwide, termites are one of few social insects. In this research, the stages of embryonic development in the parthenogenetic and sexual eggs of Reticulitermes aculabialis and R. flaviceps were observed and described. In R. flaviceps, the egg development of the FF and FM groups happened during the early phases of development, whereas in R. aculabialis, this appeared mainly during the late phase of development. The variance in the number of micropyles between the R. flaviceps FF colony type and the R. aculabialis FF colony type was statistically significant. Five stages of egg development were found in both types of R. aculabialis but only the sexual eggs of R. flaviceps. In R. flaviceps, 86% of the parthenogenetic eggs stopped growing during the blastoderm development, with the yolk cell assembling frequently in the center of the egg. According to the results of the single-cell transcriptome sequencing, we investigated the egg-to-larval expression level of genes (pka, map2k1, mapk1/3, hgk, mkp, and pax6) and indicated that the levels of essential gene expression in RaFF were considerably higher than in RfFF (p < 0.05). We also discovered that the oocyte cleavage rate in the FF colony type was considerably lower in R. flaviceps compared to R. aculabialis, which gave rise to a smaller number of mature oocytes in R. flaviceps. During ovulation in both species, oocytes underwent activation and one or two cleavage events, but the development of unfertilized eggs ceased in R. flaviceps. It was shown that termite oocyte and embryonic development were heavily influenced by genes with significant expressions. Results from the databases KEGG, COG, and GO unigenes revealed the control of numerous biological processes. This study is the first to complete a database of parthenogenetic and sexual eggs of R. flaviceps and R. aculabialis.

Conservation genomic resources over the past decade has drastically improved, since genomes can be used to predict diverse parameters vital to conservation management. Luehdorfia taibai is an endemic butterfly only found in restricted aeras in middle-west China and is critically endangered. It was classfied as a vunerlable (VN) species in the “China species red list.” Here we generated 34.38 Gb of raw DNA sequencing reads and obtained a high-qualified draft genome assembly of L. taibai. The final genome is ~683.3 Mb, with contig N50 size of 10.19 Mb. Further, 98.6% of single-copy orthologous genes have been recovered by BUSCO. An estimated 42.34% of the genome of L. taibai consists of repetitive elements. Combined with gene prediction and transcriptome sequencing, genome annotation produced 15,968 protein-coding genes. Additionally, a nearly 1:1 orthology ratio of syntenic blocks between L. taibai and its closest genome Luehdorfia chinensis suggested that the genome structures have not changed much after speciation. The genome of L. taibai have not undergone a whole genome duplication event. Population dynamics analyses indicates that L. taibai has an extremely low heterozygosity of 0.057%, and its population size has declined dramatically over the past 10 thousand years. Our study describes a draft genome assembly of the L. taibai, the first implication of this species. We consider the globally overexploited of the host plants is not the main reason to threaten L. taibai. The genome will provide advice for the conservation to the economically important Luehdorfia lineage and this specific species.

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We isolated 15 and 18 highly polymorphic genomic microsatellite markers from two subterranean termites, Reticulitermes aculabialis and R. labralis, respectively. A total of 53 alleles were detected in 15 microsatellite loci of R. aculabialis, and the alleles were 3.533±1.302 (mean±SD), while the corresponding data of R. labralis were 115 detected alleles in 18 microsatellite loci with 6.389±1.754 alleles. The observed and expected heterozygosity was 0.496±0.236 and 0.564±0.125 in R. aculabialis, and 0.368±0.263 and 0.702±0.115 in R. labralis, respectively. Seven loci were highly polymorphic (PIC>0.5) in R. aculabialis, and 15 loci were highly polymorphic (PIC>0.5) in R. labralis. All loci showed Hardy–Weinberg equilibrium. These polymorphic markers provide useful tools for population genetic and breeding system studies of subterranean termites.

Eusocial insects have a diverse mechanism of reproduction to know the termite genealogy, and we examined the Reticulitermes aculabialis breeding mechanism. This well-known species was reared in an artificial environment under darkness at Northwest University, Xian, China, from May 2018 to June 2019. After the inaugural colonies foundation, imagoes started egg-laying during 30-40 days. The hatching ratio increased gradually during the time. The femal+male (FM) worker reproductive (ergatoids) colonies were reported significantly (p<0.005) in egg-laying and chambers making than primary reproductives (imagoes). The morphological measurement shows that the swarmer alates were significantly (p<0.005) extended along with wings, mean live weight of the queen was significantly heavier (p<0.005) than workers but not statistically different mature reproductive queen. The sex ratio of workers was found significantly dominant (p<0.005) among individuals in the colony and busy to find food sources, caring for young termites and eggs, constructing galleries, and helping the soldiers to defend the colony from predators, increases the efficiency of the effectiveness, protection from pathogens and parasites. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome of a parthenogenetic termiteReticulitermes aculabialiswas assembled and analyzed. The mitogenome is 16,475 bp long and contains the same gene repertoire and gene order as otherReticulitermesspecies (13 protein-coding genes, 22 tRNA genes, 2 rRNA genes and control region). Coding genes (PCGs, tRNAs and rRNAs) are 14,688 bp in length, occupying 89.15% of the total genomic size. The A + T content of the mitogenome is 65.78%. [ABSTRACT FROM AUTHOR]

We have determined the complete mitochondrial genome of the endangered butterfly, Luehdorfia taibai. The total lenth of the L. taibai mitogenome is 15,553 bp with 81% A + T content. It consists of 13 protein-coding, 22 tRNA, 2 rRNA genes and an A + T-rich region. All the protein-coding genes used ATN as start codon and TAA as stop codon, except for COI gene, which used CGA as start codon. The A + T-rich region was 939 bp in lenth with 95% A + T content. L. taibai mitogenome contained an extra tRNALeu, located from 191 bp to 259 bp, of which function was not clear. [ABSTRACT FROM AUTHOR]

Aim: The basic aim of this analysis was to evaluate the 100 most cited publications in aging research. Methods: On January 17, 2021 Web of Science Core Collection database was searched for aging research publications. The studied parameter includes; publication year, authorship, publication type, keywords, journal name, institution, country, and visualization mapping. HistCiteTM application for citation analysis and VOSviewer software was used for visualization mapping. Results: The top 100 most cited papers were published in 52 journals, authored by 537 authors. The most cited paper was "The diagnosis of dementia due to Alzheimer's disease: Recommendations from the National Institute on Aging-Alzheimer's Association workgroups on diagnostic guidelines for Alzheimer's disease," which received 6039 citations (2013 average citations per year). Nature was the most attractive journal (n=13). Aging was the most dominant used keyword. The maximum number of papers were published in 2005 (n=8). Harvard University was the leading institute (n=13), while the United States of America (USA) was the most productive country (n=76). Conclusion: The highly cited papers were published in developed countries, and no study was published in low-income countries. [ABSTRACT FROM AUTHOR]