Browsing by Subject "Growth"

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    Concerning demographic limitations on the population growth rate of West Australian (breeding stock D) humpback whales
    (International Whaling Commission, 2011) Brandão, Anabela; Butterworth, Doug S
    The upper bound of 0.126 on the maximum demographically possible annual growth rate for humpback whales that has standardly been imposed on recent applications of age-aggregated assessment models for this species in the IWC Scientific Committee, is based on an analysis that assumes steady age structure. It is conceivable that transient age-structure effects could admit greater population growth rates for short periods than suggested by such a bound. This possibility is addressed by developing an age-structured population model in which possible density dependent changes in pregnancy rate, age at first parturition and natural mortality are modelled explicitly, and allowance is made for the possibility of natural mortality increasing at older ages. The model is applied to the case of the west Australian humpback whale population (Breeding Stock D), for which breeding ground surveys over the 1982–1994 period provide a point estimate of 0.10 for the annual population growth rate. Results based upon the breeding population survey estimate of abundance of 10,032 in 1999 suggest that 0.12 is the maximum demographically feasible annual rate of increase for this stock over 1982–1994 if it is a closed population. This result is based on essentially the same parameter choices as led to the earlier r = 0.126 bound, i.e. that in the limit of low population size the age at first parturition approaches five years from above, the annual pregnancy rate 0.5 from below, and the annual natural mortality rate 0.01 from above. Transient effects do not appear able to reconcile the observed rate of increase with less extreme values of demographic parameters than led to the previously imposed upper bound of 0.126 on the maximum possible annual growth rate. Although use of extreme values reported for demographic parameters for Northern Hemisphere humpback whale populations, rather than those considered here, would reduce this suggested maximum rate of 0.12, the conclusion that transient effects have a very limited impact on observed population growth rates would be unlikely to change.
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    Open Access
    Expanding the clinical spectrum of hereditary fibrosing poikiloderma with tendon contractures, myopathy and pulmonary fibrosis due to FAM111B mutations
    (2015) Mercier, Sandra; Küry, Sébastien; Salort-Campana, Emmanuelle; Magot, Armelle; Agbim, Uchenna; Besnard, Thomas; Bodak, Nathalie; Bou-Hanna, Chantal; Bréhéret, Flora; Brunelle, Perrine; Caillon, Florence; Chabrol, Brigitte; Cormier-Daire, Valérie; David, Albert; Eymard, Bruno; Faivre, Laurence; Figarella-Branger, Dominique; Fleurence, Emmanuelle; Ganapathi, Mythily; Gherardi, Romain; Goldenberg, Alice; Hamel, Antoine; Igual, Jeanine; Irvine, Alan D; Israël-Biet, Dominique; Kannengiesser, Caroline; Laboisse, Christian; Le Caignec, Cédric; Mahé, Jean-Yves; Mallet, Stéphanie; MacGowan, Stuart; McAleer, Maeve A; McLean, Irwin; Méni, Cécile; Munnich, Arnold; Mussini, Jean-Marie; Nagy, Peter L; Odel, Jeffrey; O’Regan, Grainne M; Péréon, Yann; Perrier, Julie; Piard, Juliette; Puzenat, Eve; Sampson, Jacinda B; Smith, Frances; Soufir, Nadem; Tanji, Kurenai; Thauvin, Christel; Ulane, Christina; Watson, Rosemarie M; Khumalo, Nonhlanhla P; Mayosi, Bongani M; Barbarot, Sébastien; Bézieau, Stéphane
    BackgroundHereditary Fibrosing Poikiloderma (HFP) with tendon contractures, myopathy and pulmonary fibrosis (POIKTMP [MIM 615704]) is a very recently described entity of syndromic inherited poikiloderma. Previously by using whole exome sequencing in five families, we identified the causative gene, FAM111B (NM_198947.3), the function of which is still unknown. Our objective in this study was to better define the specific features of POIKTMP through a larger series of patients.MethodsClinical and molecular data of two families and eight independent sporadic cases, including six new cases, were collected.ResultsKey features consist of: (i) early-onset poikiloderma, hypotrichosis and hypohidrosis; (ii) multiple contractures, in particular triceps surae muscle contractures; (iii) diffuse progressive muscular weakness; (iv) pulmonary fibrosis in adulthood and (v) other features including exocrine pancreatic insufficiency, liver impairment and growth retardation. Muscle magnetic resonance imaging was informative and showed muscle atrophy and fatty infiltration. Histological examination of skeletal muscle revealed extensive fibroadipose tissue infiltration. Microscopy of the skin showed a scleroderma-like aspect with fibrosis and alterations of the elastic network. FAM111B gene analysis identified five different missense variants (two recurrent mutations were found respectively in three and four independent families). All the mutations were predicted to localize in the trypsin-like cysteine/serine peptidase domain of the protein. We suggest gain-of-function or dominant-negative mutations resulting in FAM111B enzymatic activity changes.ConclusionsHFP with tendon contractures, myopathy and pulmonary fibrosis, is a multisystemic disorder due to autosomal dominant FAM111B mutations. Future functional studies will help in understanding the specific pathological process of this fibrosing disorder.
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    Retinoic acid-independent expression of Meis2 during autopod patterning in the developing bat and mouse limb
    (2015) Mason, Mandy K; Hockman, Dorit; Curry, Lyle; Cunningham, Thomas J; Duester, Gregg; Logan, Malcolm; Jacobs, David S; Illing, Nicola
    BackgroundThe bat has strikingly divergent forelimbs (long digits supporting wing membranes) and hindlimbs (short, typically free digits) due to the distinct requirements of both aerial and terrestrial locomotion. During embryonic development, the morphology of the bat forelimb deviates dramatically from the mouse and chick, offering an alternative paradigm for identifying genes that play an important role in limb patterning.ResultsUsing transcriptome analysis of developing Natal long-fingered bat (Miniopterus natalensis) fore- and hindlimbs, we demonstrate that the transcription factor Meis2 has a significantly higher expression in bat forelimb autopods compared to hindlimbs. Validation by reverse transcriptase and quantitative polymerase chain reaction (RT-qPCR) and whole mount in situ hybridisation shows that Meis2, conventionally known as a marker of the early proximal limb bud, is upregulated in the bat forelimb autopod from CS16. Meis2 expression is localised to the expanding interdigital webbing and the membranes linking the wing to the hindlimb and tail. In mice, Meis2 is also expressed in the interdigital region prior to tissue regression. This interdigital Meis2 expression is not activated by retinoic acid (RA) signalling as it is present in the retained interdigital tissue of Rdh10trex/trex mice, which lack RA. Additionally, genes encoding RA-synthesising enzymes, Rdh10 and Aldh1a2, and the RA nuclear receptor Rarβ are robustly expressed in bat fore- and hindlimb interdigital tissues indicating that the mechanism that retains interdigital tissue in bats also occurs independently of RA signalling.ConclusionsMammalian interdigital Meis2 expression, and upregulation in the interdigital webbing of bat wings, suggests an important role for Meis2 in autopod development. Interdigital Meis2 expression is RA-independent, and retention of interdigital webbing in bat wings is not due to the suppression of RA-induced cell death. Rather, RA signalling may play a role in the thinning (rather than complete loss) of the interdigital tissue in the bat forelimb, while Meis2 may interact with other factors during both bat and mouse autopod development to maintain a pool of interdigital cells that contribute to digit patterning and growth.Electronic supplementary materialThe online version of this article (doi:10.1186/s13227-015-0001-y) contains supplementary material, which is available to authorized users.