Myrmecochorous dispersal distances: a world survey

Abstract. Myrmecochorous dispersal distances are reviewed; the seed dispersal curve generated by ants shows a characteristic peak at short distances and a long tail, a shape suited to small densities of safe sites. Mean global distance is of 0.96 m (n= 2524) with a range of 0.01–77 m. Data have been broken down by geography (Northern hemisphere v. Southern hemisphere), taxonomy (ant subfamilies) and ecology (vegetation: sclerophyllous v. mesophyllous). Although a statistical difference exists between dispersal curves from the Northern hemisphere and the Southern hemisphere, this may be an artefact of lack of data from mesophyllous myrmecochores from this hemisphere. The four ant subfamilies do show also numerical differences but could not be subjected to statistical analysis. A difference between the shape of dispersal curve for sclerophyllous myrmecochores and mesophyllous myrmecochores has also been detected. We hypothesize that this difference is related to the myrmecological communities from both types of vegetation: dispersing ants from sclerophyllous vegetation would have smaller nest densities and/or bigger foraging areas than dispersing ants from mesic environments.     

Myrmecochorous adaptations ofCorydalis species (Papaveraceae) in southern Japan

Dispersal morphology based on the myrmecochorous adaptations for predator avoidance of sevenCorydalis species including two varieties are investigated in southern Japan. Three types of myrmecochory were distinguished: myrmecochory with autochory (diplochory), the explosive ejection of seeds followed by ant transportation; myrmecochory with vegetative reproduction, seed-transportation by ants and reproduction by tuber; and pure myrmecochory, seed-transporting by ants only. Diplochory occurs in one winter annual plant, which has explosive capsules, a smooth seed surface, a small elaiosome, long pedicels and large bracts. Myrmecochory with vegetative reproduction occurs in two perennials that reproduce by tuber, although they also produce a small number of seeds with a medium-sized elaiosome. the pedicels and bracts are medium in size. Pure myrmecochory occurs in five annuals or biennials that are characterized by a rough seed surface with a large elaiosome, comparatively high seed production, short pedicels and only small bracts. Diplochory is exhibited by only one species distributed widely throughout Japan. Myrmecochory with vegetative reproduction is exhibited by species mainly distributed in cool-temperate northern Japan, while true myrmecochory is exhibited by the majority ofCorydalis species in warm-temperate Japan.     

Satiation in Collection of Myrmecochorous Diaspores by Colonies of <Emphasis Type="Italic">Aphaenogaster rudis</Emphasis> (Formicidae: Myrmicinae) in Central Ohio,USA

When ants are dispersing seeds (myrmecochory), cessation of foraging can be as important as recruitment in determining dispersal success. We studied food collection by Aphaenogaster rudis from experimental depots by monitoring temporal variation and preference in food removal (diaspores of Asarum canadense and Sanguinaria canadensis and larvae of Tenebrio obscurus). Removal of diaspores, but not insect larvae, declined to nearly zero over the scale of hours. Satiation extended over the scale of days for diaspores. Extensive collection of larvae inhibited future collection of diaspores, but the converse was not observed. Increasing distance from the nest reduced removal of diaspores, but not of food bodies isolated from diaspores. Removal rates for diaspores were uncorrelated with the number of workers or brood in a colony.     

CFC syndrome: a syndrome distinct from Noonan syndrome

We report two children with a common pattern of birth defects. Both have very sparse, curly hair, nystagmus and mental retardation. The first one has Noonan syndrome habitus associated with keratosis plantaris and nystagmus; the second one has a slightly Noonan-like face, macrocephaly, keratosis pilaris, and hypertrophic cardiomyopathy. They represent the extreme of a spectrum of congenital defects recently reported independently as CFC syndrome by Reynolds and as "Noonan-like short stature syndrome with sparse hair" by Baraitser and Patton. The clinical features are reviewed and the autonomy of the syndrome with regards to Noonan syndrome, is disputed, since every sign seems to occur independently in Noonan syndrome. The father of the second case probably has a minor syndrome expression, pointing to probable autosomal dominant inheritance.     

Metabolic syndrome in polycystic ovary syndrome

Both metabolic syndrome (MS) and polycystic ovary syndrome (PCOS) are common among women. The exact prevalence of MS in women with PCOS is dependent upon the diagnostic criteria used for each. However, the frequent co-occurrence of both MS and PCOS in women is suggestive of a common aetiology. In this short review article we argue that insulin resistance, as a consequence of abdominal obesity, may represent such a common aetiology. We also review the literature on the prevalence of MS in women with PCOS and consider the impact that the particular criteria used to diagnose both MS and PCOS may have had on these estimates of prevalence.     

Combined klinefelter-Down syndrome or XXYY syndrome?

Summary A case of 48,XXYY constellation is described to demonstrate that both the fluorescence-banding technique and the papillar pattern allow a clear differential diagnosis from the 48,XXY,G+ syndrome, regardless of the clinical appearance.

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Zusammenfassung An Hand eines Falles von 48,XXYY-Konstellation wird demonstriert, daß sowohl die Fluoresenzbandentechnik als auch der Hautleistenbefund eine sichere Differentialdiagnose zum 48,XXY,G+-Syndrom, unabhängig vom klinischen Erscheinungsbild, erlauben.

     

The Prader-Willi syndrome and the Angelman syndrome

The Prader-Willi syndrome and the Angelman syndrome are characterised by a complex clinical and behavioural phenotype resulting from loss of paternal or maternal expression, respectively, of genes located on the human chromosome 15q11-13. Different molecular mechanisms leading to this imbalance have been identified, including microdeletions, intragenic mutations, uniparental disomy and imprinting centre defects. Low copy repeat gene clusters are known to flank the 15q11-13 microdeletion. They predispose to unequal crossing-over events resulting in the deletion. Involvement of multiple disease genes is strongly suspected and traditional positional cloning techniques as well as animal models are used to identify the involved genes. In this review we include the present state of art and a delineation of future approach to study the candidate genes in these two syndromes.     

Bloom's syndrome

Summary The biochemical defect in Bloom's syndrome (BS) remains unknown, but two characteristic features of BS cells point to a disturbance of DNA replication, namely, an excessive number of sister-chromatid exchanges (SCEs) in bromodeoxyuridine (BrdU)-substibuted cells and an abnormally slow rate of replicon elongation. The hypothesis of an abnormal DNA polymerase as the explanation for these observations was tested using an in situ assay system for DNA polymerase activity and to estimate molecular weights in cellular extracts of cultured BS cells. DNA polymerase subunits in cellular extracts from the BS cells when separated electrophoretically on polyacrylamide gels showed the same mobilities (i.e., molecular weights) as the controls and were equally effective at promoting the incorporation of isotopically labeled nucleosides. It is concluded that the genetic defect in BS has no direct effect on either DNA-polymerase activity or the amounts and molecular weights of the different forms of the enzyme.     

Vogt-Koyanagi syndrome

Cytologic examination of 9,000 specimens of mucoid material taken from the cervices of 3,000 women who had no clinically observable vaginal abnormality was carried out. Sixteen of them had carcinoma, later proved by tissue examination. In 15 cases the lesion was epidermoid carcinoma of the cervix and in one was adenocarcinoma of the endometrium. Routine use of examination of mucoid specimens easily and painlessly obtained from the vagina should contribute substantially to a lower mortality from pelvic carcinoma.     

Cerebro-costo-mandibular syndrome

Summary A 7-month-old boy with the cerebro-costomandibular syndrome is presented. This is the first case report in an Oriental population.15 reported cases in the literature are reviewed.     

Hypoparathyroidism-retardation-dysmorphism syndrome

Congenital hypoparathyroidism, growth retardation and facial dysmorphism is a rare autosomal recessive disorder seen among children born to consanguineous couple of Arab ethnicity. This syndrome is commonly known as Sanjad-Sakati or hypoparathyroidism-retardation-dysmorphism syndrome (HRD). We report 13-year-old Hindu boy with hypoparathyroidism, tetany, facial dysmorphism and developmental delay, compatible with HRD syndrome.