Cassau Sina, Degen Angelina, Krüger Stephanie, Krieger Jürgen
Martin Luther University Halle-Wittenberg, Institute of Biology/Zoology, Department of Animal Physiology, 06120 Halle (Saale), Germany.
Martin Luther University Halle-Wittenberg, Institute of Biology/Zoology, Department of Developmental Biology, 06120 Halle (Saale), Germany.
Curr Res Insect Sci. 2023 Feb 18;3:100053. doi: 10.1016/j.cris.2023.100053. eCollection 2023.
The desert locust detects odorants through olfactory sensory neurons (OSNs) that are surrounded by non-neuronal support cells (SCs). OSNs and SCs are housed in cuticle structures, named sensilla found abundantly on the antenna in all developmental stages of the hemimetabolic insect. In insects, multiple proteins expressed by OSNs and SCs are indicated to play a pivotal role in the detection of odorants. This includes insect-specific members of the CD36 family of lipid receptors and transporters called sensory neuron membrane proteins (SNMPs). While the distribution pattern of the SNMP1 and SNMP2 subtypes in OSNs and SCs across different sensilla types has been elucidated for the adult antenna, their localization in cells and sensilla of different developmental stages is unclear. Here, we determined the SNMP1 and SNMP2 expression topography on the antenna of the first, third and fifth instar nymphs. Through FIHC experiments we found that in all developmental stages SNMP1 is expressed in OSNs and SCs of the trichoid and basiconic sensilla while SNMP2 is restricted to the SCs of the basiconic and coeloconic sensilla thus resembling the adult arrangement. Our results demonstrate that both SNMP types have defined cell- and sensilla-specific distribution patterns established already in the first instar nymphs and retained into the adult stage. This conserved expression topography underlines the importance of SNMP1 and SNMP2 in olfactory processes throughout the development of the desert locust.
沙漠蝗通过嗅觉感觉神经元（OSNs）检测气味分子，这些神经元被非神经元支持细胞（SCs）所包围。OSNs和SCs位于表皮结构中，这种表皮结构称为感器，在渐变态昆虫的所有发育阶段，触角上都大量存在。在昆虫中，OSNs和SCs表达的多种蛋白质在气味分子检测中起关键作用。这包括脂质受体和转运蛋白CD36家族的昆虫特异性成员，称为感觉神经元膜蛋白（SNMPs）。虽然已经阐明了成年触角中不同感器类型的OSNs和SCs中SNMP1和SNMP2亚型的分布模式，但它们在不同发育阶段的细胞和感器中的定位尚不清楚。在这里，我们确定了一龄、三龄和五龄若虫触角上SNMP1和SNMP2的表达图谱。通过荧光免疫组织化学实验，我们发现，在所有发育阶段，SNMP1在毛形感器和锥形感器的OSNs和SCs中表达，而SNMP2仅限于锥形感器和腔锥形感器的SCs，因此类似于成虫的分布。我们的结果表明，这两种SNMP类型在一龄若虫中就已建立了明确的细胞和感器特异性分布模式，并一直保留到成虫阶段。这种保守的表达图谱强调了SNMP1和SNMP2在沙漠蝗整个发育过程中的嗅觉过程中的重要性。
