The DOCK Protein Sponge Binds to ELMO and Functions in Drosophila Embryonic CNS Development

Cell morphogenesis, which requires rearrangement of the actin cytoskeleton, is essential to coordinate the development of tissues such as the musculature and nervous system during normal embryonic development. One class of signaling proteins that regulate actin cytoskeletal rearrangement is the evolutionarily conserved CDM (C. elegans Ced-5, human DOCK180, Drosophila Myoblast city, or Mbc) family of proteins, which function as unconventional guanine nucleotide exchange factors for the small GTPase Rac. This CDM-Rac protein complex is sufficient for Rac activation, but is enhanced upon the association of CDM proteins with the ELMO/Ced-12 family of proteins. We identified and characterized the role of Drosophila Sponge (Spg), the vertebrate DOCK3/DOCK4 counterpart as an ELMO-interacting protein. Our analysis shows Spg mRNA and protein is expressed in the visceral musculature and developing nervous system, suggesting a role for Spg in later embryogenesis. As maternal null mutants of spg die early in development, we utilized genetic interaction analysis to uncover the role of Spg in central nervous system (CNS) development. Consistent with its role in ELMO-dependent pathways, we found genetic interactions with spg and elmo mutants exhibited aberrant axonal defects. In addition, our data suggests Ncad may be responsible for recruiting Spg to the membrane, possibly in CNS development. Our findings not only characterize the role of a new DOCK family member, but help to further understand the role of signaling downstream of N-cadherin in neuronal development

Temporal Coordination of Gene Networks by Zelda in the Early Drosophila Embryo

In past years, much attention has focused on the gene networks that regulate early developmental processes, but less attention has been paid to how multiple networks and processes are temporally coordinated. Recently the discovery of the transcriptional activator Zelda (Zld), which binds to CAGGTAG and related sequences present in the enhancers of many early-activated genes in Drosophila, hinted at a mechanism for how batteries of genes could be simultaneously activated. Here we use genome-wide binding and expression assays to identify Zld target genes in the early embryo with the goal of unraveling the gene circuitry regulated by Zld. We found that Zld binds to genes involved in early developmental processes such as cellularization, sex determination, neurogenesis, and pattern formation. In the absence of Zld, many target genes failed to be activated, while others, particularly the patterning genes, exhibited delayed transcriptional activation, some of which also showed weak and/or sporadic expression. These effects disrupted the normal sequence of patterning-gene interactions and resulted in highly altered spatial expression patterns, demonstrating the significance of a timing mechanism in early development. In addition, we observed prevalent overlap between Zld-bound regions and genomic “hotspot” regions, which are bound by many developmental transcription factors, especially the patterning factors. This, along with the finding that the most over-represented motif in hotspots, CAGGTA, is the Zld binding site, implicates Zld in promoting hotspot formation. We propose that Zld promotes timely and robust transcriptional activation of early-gene networks so that developmental events are coordinated and cell fates are established properly in the cellular blastoderm embryo

Plate 5 from: Mašán P (2017) A revision of the family Ameroseiidae (Acari, Mesostigmata), with some data on Slovak fauna. ZooKeys 704: 1-228. https://doi.org/10.3897/zookeys.704.13304

The family Ameroseiidae Evans, 1961 (Acari: Mesostigmata) includes a total of 12 valid and adequately described genera, namely Afrocypholaelaps Elsen, 1972, Ameroseiella Bregetova, 1977, Ameroseius Berlese, 1904, Asperolaelaps Womersley, 1956, Brontispalaelaps Womersley, 1956, Epicriopsis Berlese, 1916, Hattena Domrow, 1963, Kleemannia Oudemans, 1930, Neocypholaelaps Vitzthum, 1942, Pseudoameroseius gen. n., Sertitympanum Elsen & Whitaker, 1985 and Sinoseius Bai & Gu, 1995. One of these genera includes subgenera, namely Kleemannia (Primoseius) Womersley, 1956. All genera are reviewed and re-diagnosed, and a dichotomous key is provided for their identification. Ameroseius (50 species), Kleemannia (28 species) and Neocypholaelaps (22 species) are the largest genera in the family. Ameroseiella, Kleemannia, Kleemannia (Primoseius) and Sinoseius are considered to be valid taxa and, in presented systematic classification, they are removed from synonymy with Ameroseius. The genus Pseudoameroseius gen. n., with type species Ameroseius michaelangeli Moraza, 2006 (from Canary Islands), is newly erected to further refine broad primary concept of Ameroseius as understood by some former authors (Karg, Bregetova). Asperolaelaps is removed from synonymy with Neocypholaelaps. Three new species are here described, namely Ameroseius renatae sp. n. (based on specimens from Slovakia), Kleemannia dolichochaeta sp. n. (from Spain) and Kleemannia miranda sp. n. (from U.S.A.). The following new junior synonymies are proposed: Ameroseius apodius Karg, 1971 = Ameroseiella macrochelae (Westerboer, 1963); Ameroseius bregetovae Livshits & Mitrofanov, 1975 = Neocypholaelaps favus Ishikawa, 1968; Ameroseius chinensis Khalili-Moghadam & Saboori, 2016 = Ameroseius guyimingi Ma, 1997; Ameroseius crassisetosus Ye & Ma, 1993, Ameroseius qinghaiensis Li & Yang, 2000 and Ameroseius norvegicus Narita, Abduch & Moraes, 2015 = Ameroseius corbiculus (Sowerby, 1806); Ameroseius dubitatus Berlese, 1918 = Kleemannia plumosa (Oudemans, 1902); Ameroseius eumorphus Bregetova, 1977 and Kleemannia potchefstroomensis Kruger & Loots, 1980 = Kleemannia pseudoplumosa (Rack, 1972); Ameroseius gilarovi Petrova, 1986 = Kleemannia plumigera Oudemans, 1930; Ameroseius imparsetosus Westerboer, 1963 = Ameroseius georgei (Turk, 1943); Ameroseius lanatus Solomon, 1969 and Ameroseius fimetorum Karg, 1971 = Kleemannia tenella (Berlese, 1916); Ameroseius lanceosetis Livshits & Mitrofanov, 1975 = Kleemannia pavida (C. L. Koch, 1839); Ameroseius marginalis Fan & Li, 1993 and Ameroseius sichuanensis Fan & Li, 1993 = Kleemannia insignis (Bernhard, 1963); Ameroseius pseudofurcatus Livshits & Mitrofanov, 1975 = Ameroseius furcatus Karg, 1971; Ameroseius stramenis Karg, 1976 and Lasioseius (Lasioseius) gracilis Halbert, 1923 = Kleemannia delicata (Berlese, 1918); Epicriopsis langei Livshits & Mitrofanov, 1975 and Epicriopsis baloghi Kandil, 1978 = Epicriopsis palustris Karg, 1971; Epicriopsis rivus Karg, 1971 = Epicriopsis mirabilis Willmann, 1956; Neocypholaelaps ewae Haitlinger, 1987 = Neocypholaelaps indicus Evans, 1963; Neocypholaelaps lindquisti Prasad, 1968, Afrocypholaelaps ranomafanaensis Haitlinger, 1987 and Afrocypholaelaps analicullus Ho, Ma, Wang & Severinghaus, 2010 = Afrocypholaelaps africanus (Evans, 1963); Sinoseius pinnatus Huhta & Karg, 2010 = Sinoseius lobatus Bai, Gu & Fang, 1995. Ameroseius womersleyi Mašán, is a replacement name proposed for Ameroseius ornatus Womersley, 1956, a junior secondary homonym of Cornubia ornata Turk, 1943 [= Ameroseius corbiculus (Sowerby, 1806)]. Cornubia georgei Turk, 1943 is removed from synonymy with Ameroseius corbiculus (Sowerby, 1806). An annotated catalogue of the world species of Ameroseiidae is provided, partly based on type (in more than 60 species) and non-type specimens from various museum deposits and personal collections, including new or revised material from Slovakia. It contains 206 named species (138 valid species, 37 synonyms, nine unrecognizable species, 15 species previously excluded from Ameroseiidae, and seven “nomina nuda”), with details of their authorship, synonyms, nomenclatural and bibliographic details, generic placement, and morphology. Altogether 23 new combinations are proposed. The genus Sertitympanum with Sertitympanum nodosum (Sheals, 1962) and two further species, namely Kleemannia kosi El-Badry, Nasr & Hafez, 1979 and Kleemannia parplumosa Nasr & Abou-Awad, 1986, are reported from Europe for the first time. New keys are given for identification of 37 species belonging to eight genera which have been found in Europe to date (Ameroseiella, Ameroseius, Epicriopsis, Kleemannia, Neocypholaelaps, Pseudoameroseius gen. n., Sertitympanum and Sinoseius). All of these genera except Pseudoameroseius gen. nov. and Sertitympanum occur in Slovakia. So, the fauna of Slovakia includes six genera and 27 species, including ten first reports for the country