Dimorphism and evolution of <i>Albarracinites</i> (Ammonoidea, Lower Bajocian) from the Iberian Range (Spain)

<div><p>Several tens of specimens of Lower Bajocian <i>Albarracinites</i> (type species <i>A. albarraciniensis</i> Fernandez-Lopez, <a href="#cit0022" target="_blank">1985</a>), including microconchs and macroconchs from the Iberian Range, have been studied. This ammonite genus ranges in the Iberian Range from at least the Ovale Zone to the uppermost Laeviuscula Zone of the Lower Bajocian (Middle Jurassic). The macroconch counterpart is thought to be a group of stephanoceratids previously attributed to <i>Mollistephanus</i>, <i>Riccardiceras</i> and other new forms described in this paper. Two chronologically successive species of <i>Albarracinites</i> have been identified: <i>A. albarraciniensis</i> and <i>A. submediterraneus</i> sp. nov. The evolution of the <i>Albarracinites</i> lineage represents a hypermorphic peramorphocline starting from depressed, small and slender serpenticones of <i>A. westermanni</i>, to larger planorbicones with more cadiconic phragmocones and body chamber of subcircular cross section belonging to <i>A. submediterraneus</i> sp. nov., through <i>A. albarraciniensis</i> Fernandez-Lopez. In contrast, <i>Mollistephanus planulatus</i> (Buckman), <i>M. cockroadensis</i> Chandler & Dietze and <i>M. mollis</i> Buckman represent a peramorphocline by acceleration, producing adults of similar size but more compressed and with increasing ontogenic variation of shell ornament. <i>Albarracinites</i> and <i>Mollistephanus</i> subsequently developed two opposite peramorphoclines or gradational series of morphological changes undergoing greater development and ontogenic variation. These two genera show diverse palaeobiogeographical distributions too. <i>Albarracinites</i> is rarely recorded in the Mediterranean and Submediterranean from the Discites to the Laeviuscula Zone, whereas <i>Mollistephanus</i> is more common in north-western Europe and other biochoremas of the western Tethys from the Discites Zone to the Sauzei Zone. <i>Albarracinites</i> seems to be the earliest stephanoceratid lineage in western Tethys, branching off from the otoitid <i>Riccardiceras</i> by proterogenetic change and resulting in paedomorphosis at the Aalenian/Bajocian boundary.</p><p><a href="http://zoobank.org/urn:lsid:zoobank.org:pub:09B95E3C-00E7-4A9E-907B-656255AA7B00" target="_blank">http://zoobank.org/urn:lsid:zoobank.org:pub:09B95E3C-00E7-4A9E-907B-656255AA7B00</a></p></div

Dimorphism and evolution of Albarracinites (Ammonoidea, Lower Bajocian) from the Iberian Range (Spain)

Several tens of specimens of Lower Bajocian Albarracinites (type species A. albarraciniensis Fernandez-Lopez, 1985), including microconchs and macroconchs from the Iberian Range, have been studied. This ammonite genus ranges in the Iberian Range from at least the Ovale Zone to the uppermost Laeviuscula Zone of the Lower Bajocian (Middle Jurassic). The macroconch counterpart is thought to be a group of stephanoceratids previously attributed to Mollistephanus, Riccardiceras and other new forms described in this paper. Two chronologically successive species of Albarracinites have been identified: A. albarraciniensis and A. submediterraneus sp. nov. The evolution of the Albarracinites lineage represents a hypermorphic peramorphocline starting from depressed, small and slender serpenticones of A. westermanni, to larger planorbicones with more cadiconic phragmocones and body chamber of subcircular cross section belonging to A. submediterraneus sp. nov., through A. albarraciniensis Fernandez-Lopez. In contrast, Mollistephanus planulatus (Buckman), M. cockroadensis Chandler & Dietze and M. mollis Buckman represent a peramorphocline by acceleration, producing adults of similar size but more compressed and with increasing ontogenic variation of shell ornament. Albarracinites and Mollistephanus subsequently developed two opposite peramorphoclines or gradational series of morphological changes undergoing greater development and ontogenic variation. These two genera show diverse palaeobiogeographical distributions too. Albarracinites is rarely recorded in the Mediterranean and Submediterranean from the Discites to the Laeviuscula Zone, whereas Mollistephanus is more common in north-western Europe and other biochoremas of the western Tethys from the Discites Zone to the Sauzei Zone. Albarracinites seems to be the earliest stephanoceratid lineage in western Tethys, branching off from the otoitid Riccardiceras by proterogenetic change and resulting in paedomorphosis at the Aalenian/Bajocian boundary

X chromosome inactivation does not necessarily determine the severity of the phenotype in Rett syndrome patients

WOS: 000481590200024PubMed ID: 31427717Rett syndrome (RTT) is a severe neurological disorder usually caused by mutations in the MECP2 gene. Since the MECP2 gene is located on the X chromosome, X chromosome inactivation (XCI) could play a role in the wide range of phenotypic variation of RTT patients; however, classical methylation-based protocols to evaluate XCI could not determine whether the preferentially inactivated X chromosome carried the mutant or the wild-type allele. Therefore, we developed an allele-specific methylation-based assay to evaluate methylation at the loci of several recurrent MECP2 mutations. We analyzed the XCI patterns in the blood of 174 RTT patients, but we did not find a clear correlation between XCI and the clinical presentation. We also compared XCI in blood and brain cortex samples of two patients and found differences between XCI patterns in these tissues. However, RTT mainly being a neurological disease complicates the establishment of a correlation between the XCI in blood and the clinical presentation of the patients. Furthermore, we analyzed MECP2 transcript levels and found differences from the expected levels according to XCI. Many factors other than XCI could affect the RTT phenotype, which in combination could influence the clinical presentation of RTT patients to a greater extent than slight variations in the XCI pattern.Spanish Ministry of Health (Instituto de Salud Carlos III/FEDER) [PI15/01159]; Crowdfunding program PRECIPITA, from the Spanish Ministry of Health (Fundacion Espanola para la Ciencia y la Tecnologia); Catalan Association for Rett Syndrome; Fondobiorett; Mi Princesa RettWe thank all patients and their families who contributed to this study. The work was supported by grants from the Spanish Ministry of Health (Instituto de Salud Carlos III/FEDER, PI15/01159); Crowdfunding program PRECIPITA, from the Spanish Ministry of Health (Fundacion Espanola para la Ciencia y la Tecnologia); the Catalan Association for Rett Syndrome; Fondobiorett and Mi Princesa Rett