A Novel Function of Noc2 in Agonist-Induced Intracellular Ca2+ Increase during Zymogen-Granule Exocytosis in Pancreatic Acinar Cells

Noc2, a putative Rab effector, contributes to secretory-granule exocytosis in neuroendocrine and exocrine cells. Here, using two-photon excitation live-cell imaging, we investigated its role in Ca2+-dependent zymogen granule (ZG) exocytosis in pancreatic acinar cells from wild-type (WT) and Noc2-knockout (KO) mice. Imaging of a KO acinar cell revealed an expanded granular area, indicating ZG accumulation. In our spatiotemporal analysis of the ZG exocytosis induced by agonist (cholecystokinin or acetylcholine) stimulation, the location and rate of progress of ZG exocytosis did not differ significantly between the two strains. ZG exocytosis from KO acinar cells was seldom observed at physiological concentrations of agonists, but was normal (vs. WT) at high concentrations. Flash photolysis of a caged calcium compound confirmed the integrity of the fusion step of ZG exocytosis in KO acinar cells. The decreased ZG exocytosis present at physiological concentrations of agonists raised the possibility of impaired elicitation of calcium spikes. When calcium spikes were evoked in KO acinar cells by a high agonist concentration: (a) they always started at the apical portion and traveled to the basal portion, and (b) calcium oscillations over the 10 µM level were observed, as in WT acinar cells. At physiological concentrations of agonists, however, sufficient calcium spikes were not observed, suggesting an impaired [Ca2+]i-increase mechanism in KO acinar cells. We propose that in pancreatic acinar cells, Noc2 is not indispensable for the membrane fusion of ZG per se, but instead performs a novel function favoring agonist-induced physiological [Ca2+]i increases

Macrovertebrate Paleontology and the Pliocene Habitat of Ardipithecus ramidus

International audienceA diverse assemblage of large mammals is spatially and stratigraphically associated with Ardipithecus ramidus at Aramis. The most common species are tragelaphine antelope and colobine monkeys. Analyses of their postcranial remains situate them in a closed habitat. Assessment of dental mesowear, microwear, and stable isotopes from these and a wider range of abundant associated larger mammals indicates that the local habitat at Aramis was predominantly woodland. The Ar. ramidus enamel isotope values indicate a minimal C4 vegetation component in its diet (plants using the C4 photosynthetic pathway), which is consistent with predominantly forest/woodland feeding. Although the Early Pliocene Afar included a range of environments, and the local environment at Aramis and its vicinity ranged from forests to wooded grasslands, the integration of available physical and biological evidence establishes Ar. ramidus as a denizen of the closed habitats along this continuum

A new Miocene mammalian locality, Mae Soi and the occurrence of partial skeletons of rhinocerotids and gomophotheres from northern Thailand

A New Miocene vertebrate fossil locality was found in Mae Soi, Chiang Mai Province. A nearly complete gomphothere skeleton was excavated from this site, together with several fragmental mammalian fossils. The gomphothere from Mae Soi could be either Archaeobelodon or Gomphotherium. The age of the deposits in which this gomphothere skeleton occured is provisionally dated to the Early or Middle Miocene. Partial skeletons of rhinocerotids were found in Na Sai, which is a well known locality of the Miocene in Northern Thailand. The rhinocerotid from this locality has been assigned to Gaindatherium, but cranial fragments included in a new skeleton suggest that the rhinocerotid from Na Sai could not be Gaindatherium but, rather, some other primitive genus of Rhinocerotidae. Further analysis of the skeletal elements of this rhinocerotid is necessary

Titanosauriform teeth from the Cretaceous of Japan

Sauropod teeth from six localities in Japan were reexamined. Basal titanosauriforms were present in Japan during the Early Cretaceous before Aptian, and there is the possibility that the Brachiosauridae may have been included. Basal titanosauriforms with peg-like teeth were present during the "mid" Cretaceous, while the Titanosauria with peg-like teeth was present during the middle of Late Cretaceous. Recent excavations of Cretaceous sauropods in Asia showed that multiple lineages of sauropods lived throughout the Cretaceous in Asia. Japanese fossil records of sauropods are conformable with this hypothesis

Elephas celebensis Hooijer 1949

Stegoloxodon celebensis (Hooijer, 1949) Partial synonymy: Archidiskodon celebensis Hooijer, 1949; Elephas celebensis Maglio, 1973; “ Elephas ” celebensis Sondaar, 1984 (for a full synonymy see van den Bergh 1999, p. 177). Revised diagnosis (modified after van den Bergh 1999): A Stegoloxodon species with x 7 x or x 8 x plates on the M 2 and x 10 x or x 11 x plates on the M 3, enamel very weakly or not folded except some irregular folds at the median pillars. Cranium anteroposteriorly short and dorsoventrally high. Isthmus frontalis narrow, external nares relatively small, pneumatization of the braincase limited, orbits strongly projecting laterally. Upper tusk sockets distally diverging, separated by shallow premaxillary fossa. Functional lower tusks present in some individuals, mandibular symphysis downturned. Functional premolars present.Published as part of Markov, Georgi N. & Saegusa, Haruo, 2008, On the validity of Stegoloxodon Kretzoi, 1950 (Mammalia: Proboscidea), pp. 55-56 in Zootaxa 1861 on page 56, DOI: 10.5281/zenodo.27446

Neogene mammalian fauna in Myanmar

In this paper, we review the Neogene mammalian fossils from the Pegu and Irrawaddy beds of Myanmar, comparing them with the contemporaneous mammalian faunas of south Asia (India and Pakistan) and east Asia (China). Although fossil specimens discovered in Myanmar so far are scarce, preliminary analysis of their faunal composition suggests greater similarity of the Myanmar fauna to the south Asian fauna than to the east Asian fauna until the Pliocene. The faunal interchange between Myanmar and east Asia (southern China) seems to have increased after the Pleistocene

Field notes on the fossil localities in northern Thailand visited during the field season of February 1999

In February 1999, we visited several fossil yielding areas in northern Thailand. These areas, except for the Hab Pu Dai Cave Deposit locality, are of Miocene age (Ducrocq et al. 1994, Saegusa et al. 1999). A number of fossils were collected at these localities during our fieldwork in February 1999.The most extensively examined areas were Mae Soi and Sob Mae Tham, where we recognized 17 and 20 fossil localities, respectively. Our field survey suggests that there is still a good possibility to find new fossil sites in northern Thailand. In this article, we provide field information on each of these fossil localities

Triassic foraminifers of the Lampang Group (Northern Thailand)

Triassic foraminifers are recognized, for the first time, in limestones from four localities of the Lampang Group (Northern Thailand), tectonically assigned to the Sukhothai Subterrane (Sukhothai Folded Belt) which is located between western the Sibumasu (Shan-Thai) Terrane and eastern Indochina. Four foraminiferal associations are distinguished: (1) Glomospirella lampangensis, n. sp., (2) Pilammina densa, (3) endothyroid foraminifers-Diplotremina astrofimbriata, and (4) Aulotortus sinuosus microfaunas. Based on comparison with the coeval European faunas, they are thought to be (1) Early Triassic (?), (2) Anisian, (3) Ladinian (?), and (4) Carnian in age. Important taxa of these associations are common to those of South China and Southeast Asia. Most of them are closely similar to those of Europe, and show a remarkable contrast with those of Middle and Late Permian foraminiferal assemblages having many provincial and endemic characters. Glomospirella lampangensis, n. sp. is herein systematically described among the distinguished 41 species