28 research outputs found
Multiple Sox genes are expressed in stem cells or in differentiating neuro-sensory cells in the hydrozoan Clytia hemisphaerica
<p>Abstract</p> <p>Background</p> <p>The <it>Sox </it>genes are important regulators of animal development belonging to the HMG domain-containing class of transcription factors. Studies in bilaterian models have notably highlighted their pivotal role in controlling progression along cell lineages, various <it>Sox </it>family members being involved at one side or the other of the critical balance between self-renewing stem cells/proliferating progenitors, and cells undergoing differentiation.</p> <p>Results</p> <p>We have investigated the expression of 10 <it>Sox </it>genes in the cnidarian <it>Clytia hemisphaerica</it>. Our phylogenetic analyses allocated most of these <it>Clytia </it>genes to previously-identified Sox groups: SoxB (<it>CheSox2, CheSox3, CheSox10, CheSox13, CheSox14</it>), SoxC (<it>CheSox12</it>), SoxE (<it>CheSox1, CheSox5</it>) and SoxF (<it>CheSox11</it>), one gene (<it>CheSox15</it>) remaining unclassified. In the planula larva and in the medusa, the <it>SoxF </it>orthologue was expressed throughout the endoderm. The other genes were expressed either in stem cells/undifferentiated progenitors, or in differentiating (-ed) cells with a neuro-sensory identity (nematocytes or neurons). In addition, most of them were expressed in the female germline, with their maternal transcripts either localised to the animal region of the egg, or homogeneously distributed.</p> <p>Conclusions</p> <p>Comparison with other cnidarians, ctenophores and bilaterians suggest ancient evolutionary conservation of some aspects of gene expression/function at the <it>Sox </it>family level: (i) many <it>Sox </it>genes are expressed in stem cells and/or undifferentiated progenitors; (ii) other genes, or the same under different contexts, are associated with neuro-sensory cell differentiation; (iii) <it>Sox </it>genes are commonly expressed in the germline; (iv) <it>SoxF </it>group genes are associated with endodermal derivatives. Strikingly, total lack of correlation between a given <it>Sox </it>orthology group and expression/function in stem cells/progenitors <it>vs</it>. in differentiating cells implies that <it>Sox </it>genes can easily switch from one side to the other of the balance between these fundamental cellular states in the course of evolution.</p
Challenges for biodiversity research in Europe.
In 2010, the international year of biodiversity, new policies for preserving biodiversity in Europe and worldwide will be developed as targets set by older policies, such as to halt biodiversity loss in the EU by 2010, were not met. This paper aims at sharing the expertise LERU's members harbour to set the right priorities for new biodiversity policies
Are Hox Genes Ancestrally Involved in Axial Patterning? Evidence from the Hydrozoan Clytia hemisphaerica (Cnidaria)
Background: The early evolution and diversification of Hox-related genes in eumetazoans has been the subject of conflicting hypotheses concerning the evolutionary conservation of their role in axial patterning and the pre-bilaterian origin of the Hox and ParaHox clusters. The diversification of Hox/ParaHox genes clearly predates the origin of bilaterians. However, the existence of a "Hox code' predating the cnidarian-bilaterian ancestor and supporting the deep homology of axes is more controversial. This assumption was mainly based on the interpretation of Hox expression data from the sea anemone, but growing evidence from other cnidarian taxa puts into question this hypothesis. Methodology/Principal Findings: Hox, ParaHox and Hox-related genes have been investigated here by phylogenetic analysis and in situ hybridisation in Clytia hemisphaerica, an hydrozoan species with medusa and polyp stages alternating in the life cycle. Our phylogenetic analyses do not support an origin of ParaHox and Hox genes by duplication of an ancestral ProtoHox cluster, and reveal a diversification of the cnidarian HOX9-14 genes into three groups called A, B, C. Among the 7 examined genes, only those belonging to the HOX9-14 and the CDX groups exhibit a restricted expression along the oralaboral axis during development and in the planula larva, while the others are expressed in very specialised areas at the medusa stage. Conclusions/Significance: Cross species comparison reveals a strong variability of gene expression along the oral-aboral axis and during the life cycle among cnidarian lineages. The most parsimonious interpretation is that the Hox code, collinearity and conservative role along the antero-posterior axis are bilaterian innovations
Two new Oxytrechus species from Ecuadorian páramo (Coleoptera, Carabidae, Trechinae)
Quéinnec, Eric, Ollivier, Eric (2019): Two new Oxytrechus species from Ecuadorian páramo (Coleoptera, Carabidae, Trechinae). Zootaxa 4646 (1): 55-66, DOI: https://doi.org/10.11646/zootaxa.4646.1.
Duvalius (Neoduvalius) G. Muller 1913
Subgenus <i>Neoduvalius</i> G. Müller, 1913b <p> <i>Neoduvalius</i> M̹ller, 1913b: 180; type-species: <i>Anophthalmus reitteri</i> L. Miller, 1881.</p> <p> <i>= Serboduvalius</i> Ćurčić S.B., Pavićević & Ćurčić B.P.M., 2001: 52; type-species: <i>Serboduvalius dragacevensis</i> Ćurčić S.B., Pavićević & Ćurčić B.P.M.</p> <p> = <i>Rascioduvalius</i> Ćurčić S.B., Brajković, Mitić & Ćurčić B.P.M., 2003: 484; type-species: not designated (formally unavailable - see Belousov, 2017 - but it is obvious that the author worked with <i>Duvalius cvijici</i>)</p> <p>This heterogenous subgenus actually comprises 20 taxa distributed from the north of Croatia to the southwestern part of Serbia and northern area of Montenegro (Belousov, 2017).</p>Published as part of <i>Quéinnec, Eric & Ollivier, Eric, 2021, Duvalius (Neoduvalius) lohaji n. sp., a new remarkable subterranean taxon of the isotopic Trechini lineage from Dinaric karst, Bosnia and Herzegovina (Coleoptera Carabidae: Trechinae), pp. 173-192 in Zootaxa 4942 (2)</i> on page 176, DOI: 10.11646/zootaxa.4942.2.2, <a href="http://zenodo.org/record/4600424">http://zenodo.org/record/4600424</a>
Duvalius (Neoduvalius) lohaji Queinnec and Ollivier 2021, sp. n.
<i>Duvalius (Neoduvalius) lohaji</i> Quéinnec and Ollivier sp. n. <p>(Figs. 2, 3A, 4, 7A)</p> <p> <b>Type locality</b>: Bosnia and Herzegovina, Federation of Bosnia and Herzegovina, Herzeg-Bosnia county (<i>Hercegbosanska županija</i>) (n°10), Livno municipality, Dinara Planina (Dinaric Alps), Troglav massif, Prolog mountain, Mračna Pećina (cave), N43°49’46” E16°44’38”.</p> <p> <b>Type material</b>: Holotype male labelled as follows: “Mračna Pećina / Prolog—Dinara Planina - BiH / VIII. 2017 — VI. 2018 / Quéinnec and Ollivier leg.” (white label, p) / “ Holotype <i>Duvalius (Neoduvalius) lohaji nov. sp.</i> Quéinnec & Ollivier des.” (red label, p), in cEQ; Paratypes: two females, with same general data as holotype, but one labelled: “ VI. 2016 — VI. 2017 ” and “ Paratype <i>Duvalius (Neoduvalius) lohaji nov sp.</i> Quéinnec & Ollivier des.” (red label, p) in cEO, cEQ; Remains of one specimen (a pair of elytra), same locality and collectors but “ 12. VI. 2016 ”, in cEQ; One female labelled as follows: “ Bosnia & Hercegovina, Ođak, Livno, Dinara, Nevidna Voda, 13. 08. 2008, J. Bedek lgt.” (white label, p) / “ Paratype <i>Duvalius (Neoduvalius) lohaji nov sp.</i> Quéinnec & Ollivier des.” (red label, p) in cRL; (genitalia extracted, mounted in Euparal on transparent label and pinned under the specimen).</p>Published as part of <i>Quéinnec, Eric & Ollivier, Eric, 2021, Duvalius (Neoduvalius) lohaji n. sp., a new remarkable subterranean taxon of the isotopic Trechini lineage from Dinaric karst, Bosnia and Herzegovina (Coleoptera Carabidae: Trechinae), pp. 173-192 in Zootaxa 4942 (2)</i> on page 176, DOI: 10.11646/zootaxa.4942.2.2, <a href="http://zenodo.org/record/4600424">http://zenodo.org/record/4600424</a>
Insights on Ethiopian montane ground beetles biodiversity: Taxonomic study of afro-alpine and sub-alpine Trechini (Coleoptera: Carabidae: Trechinae)
International audienceBased on collaborative work of a French-Ethiopian team, we investigated the diversity and distribution of Ethiopian trechine beetles (Carabidae, Trechini), in the sub-alpine and afro-alpine ecosystems. Four new genera, three new subgenera and eighteen new species are described from Ethiopian Highland environments: Trechus (Abyssinotus) subgen. nov. (type species: salomon sp. nov.) and Trechus (Abyssinotus) sabae sp. nov. (Mount Choke, Amhara), Trechus (s. str.) lalibelae sp. nov. (Abuna Yusef Mountains, Amhara), T. (s. str.) habeshaicus sp. nov. (Menz-Guassa Plateau, Amhara), Trechus (s. str.) kosso sp. nov. (Bale Mountains, Oromia), Deuveopsis gen. nov. (type species: lobeliae sp. nov.) (Mount Choke, Amhara), Deuveopsis (Abayopsis) subgen. nov. (type species: basilewskianus Geginat, 2008) (Mount Choke, Amhara), Aethiopsis gen. nov. (type species: chioriae sp. nov.) (Abuna Yusef Mountains, Amhara), Aethiopsis abunaensis sp. nov. (Abuna Yusef Mountains, Amhara), Aethiopsis wolloi sp. nov. (Abuna Yusef Mountains, Amhara), Aethiopsis lastaensis sp. nov. (Abuna Yusef Mountains, Amhara), Aethiopsis meneliki sp. nov. (Delanta Mountains, Amhara), Aethiopsis delantae sp. nov. (Delanta Mountains, Amhara), Aethiopsis guassaensis sp. nov. (Menz-Guassa Plateau, Amhara), Afrotrechus gen. nov. (type species: afroalpinus sp. nov.) (Mount Choke, Amhara), Afrotrechus abyssinicus sp. nov. (Mount Choke, Amhara), Afrotrechus (Abyssiniopsis) subgen. nov. (type species: amharicus (Ortuño and Novoa, 2011) comb. nov.) (Mount Choke, Amhara), Afrotrechus (Abyssiniopsis) bunae sp. nov. (Belleta Forest, Oromia), Nilotrechus gen. nov. (type species: reebae sp. nov.) (Mount Choke, Amhara), Nilotrechus niloticus sp. nov. (Mount Choke, Amhara). New data and informations are provided for previously described species: Trechus (A.) dimorphicus Pawlowski, 2001 comb. nov., Trechus (A.) chokensis Pawlowski, 2001 comb. nov., Trechus (A.) gigas Pawlowski, 2001 comb.nov., and Trechus (s. str.) bipartitus Raffray, 1885, sublaevis Raffray, 1885 and aethiopicus Alluaud, 1918. The putative phylogenetic affinities of the different genera are discussed. Considerations about microspeciation and endemism on Mount Choke are proposed
A NEW SUBGENUS AND TWO NEW SPECIES OF TRECHUS FROM ETHIOPIA (Coleoptera, Carabidae)
Two new species of Trechus from the Oromia Province (Ethiopia) are described in the present note. In the first part we describe Archeotrechus, a new microphtalmic Trechus, characterized by the dilation of only the first tarsal segment in males and by the aedeagus with the dorsal part amost completely divided into two lobes: a sclerified connection exists only in the region of the basal ostium. To this subgenus we ascribe the new species Trechus (Archeotrechus) relictus, from the area of Mt. Sgona (Batu), of yellow-brown colour, rather flattened, with non sinuate pronotum and blunt fore and hind angles; two discal setae in the third stria. The aedeagus is much elongated, with a spherical apical button, copulatory piece triangular, lanceolate, with a sharp apex, little sclerified and very simple, typical of ancestral forms, like for instance Minitrechus Vigna Taglianti & Magrini, 2009. The female gonostyli, short and curved, bear at the apex two big setae on the inner edge. In the second part of the note we describe Trechus (s. str.) oromiensis, a new species of bipartitus Group (sensu novo), characterized by the presence of only one discal seta on elytra and by peculiar features of the aedeagus
Insights into the early evolution of SOX genes from expression analyses in a ctenophore.
International audienc
Insights into the early evolution of SOX genes from expression analyses in a ctenophore.
International audienc