Genomics Aotearoa, Bioprotection Aotearoa and Biochemistry Department, University of Otago, Dunedin 9016, Aotearoa, New Zealand.
Biol Open. 2024 Sep 15;13(9). doi: 10.1242/bio.060511. Epub 2024 Sep 12.
Honeybees (Apis mellifera) are a keystone species for managed pollination and the production of hive products. Eusociality in honeybees leads to much of the reproduction in a hive driven by the queen. Queen bees have two large active ovaries that can produce large numbers of eggs if conditions are appropriate. These ovaries are also active throughout the long lives of these insects, up to 5 years in some cases. Recent studies have indicated that the germline precursors of the adult honeybee queen ovary are organized into 8-cell clusters, joined together by a polyfusome; a cytoplasmic bridge. To understand the origin of these clusters, and trace the development of the honeybee queen ovary, we examined the cell types and regionalization of the developing larval and pupal queen ovaries. We used established (nanos and castor), and novel (odd skipped) gene expression markers to determine regions of the developing ovary. Primordial germline cells develop in the honeybee embryo and are organized into ovary structures before the embryo hatches. The ovary is regionalized by larval stage 3 into terminal filaments and germaria. At this stage, clusters of germline cells in the germaria are joined by fusomes and are dividing synchronously. The origin of the 8-cell clusters in the adult germarium is therefore during larval stages. On emergence, the queen ovary has terminal filaments and germaria but has not yet developed any vitellaria, which are produced after the queen embarks on a nuptial flight. The lack of germaria, and the storing of germline progenitors as clusters, may be adaptions for queen bees to endure the metabolic demands of a nuptial flight, as well as rapidly lay large numbers of eggs to establish a hive.
蜜蜂（Apis mellifera）是管理授粉和蜂产品生产的关键物种。蜜蜂的群居导致了蜂巢中大部分的繁殖活动由蜂王驱动。蜂王有两个大的活跃卵巢，如果条件合适，它们可以产生大量的卵子。这些卵巢在这些昆虫的长寿命中也保持活跃，在某些情况下长达 5 年。最近的研究表明，成年蜂王卵巢的生殖系前体细胞组织成 8 个细胞簇，通过多丝体连接在一起；细胞质桥。为了了解这些簇的起源，并追踪蜂王卵巢的发育，我们检查了幼虫和蛹期蜂王卵巢的细胞类型和区域化。我们使用了已建立的（nanos 和 castor）和新的（odd skipped）基因表达标记来确定卵巢发育的区域。原始生殖细胞在蜜蜂胚胎中发育，并在胚胎孵化前组织成卵巢结构。卵巢在幼虫阶段 3 时通过末端丝和生殖腺进行区域化。在这个阶段，生殖腺中的生殖细胞簇通过丝体连接并同步分裂。因此，成虫生殖腺中的 8 个细胞簇起源于幼虫阶段。在成虫出现时，蜂王卵巢具有末端丝和生殖腺，但尚未发育任何卵黄体，卵黄体是在蜂王开始婚飞后产生的。生殖腺的缺乏以及生殖系祖细胞以簇的形式储存，可能是蜂王适应婚飞代谢需求以及快速产卵以建立蜂巢的适应。
