scholarly journals A latitudinal cline in P–M gonadal dysgenesis potential in Australian Drosophila melanogaster populations

1987 ◽  
Vol 49 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Ian A. Boussy
Keyword(s):  
Population Dynamics ◽  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
East Coast ◽  
Isofemale Lines ◽  
Single Population ◽  
The North ◽  
Different Characteristics ◽  
North And South ◽  
Two Populations

SummaryIsofemale lines of Drosophila melanogaster from six localities along the east coast of Australia, spanning 2900 km and 26 degrees of latitude, were assayed for their gonadal dysgenesis characteristics in the P–M system of hybrid dysgenesis. A strong clinal pattern with latitude was discovered. From north to south, the first two populations were typical strong P populations, and the next population was moderate P. The next population to the south was neutral (Q), with some weak P and weak M characteristics. The two southernmost populations were typical M populations. Much variance in P activity in P populations and in susceptibility to P activity in M populations was detected among isofemale lines. This clinal pattern with latitude of the P–M system is paralleled by similar clinal patterns for frequencies of common cosmopolitan inversions and of certain allozymes in Australia. A model of introductions of flies with different characteristics in the north and south could account for the P–M clinal pattern, but cannot account for an intermediate Q population, nor establish the inversion and isoenzyme dines at the same time. Current models of transposable element population dynamics are limited to single population dynamics, and are therefore inadequate for these clinal data.

scholarly journals The P-M Hybrid Dysgenesis Cline in Eastern Australian Drosophila melanogaster: Discrete P, Q and M Regions Are Nearly Contiguous

Genetics ◽  
1987 ◽  
Vol 115 (4) ◽  
pp. 737-745
Author(s):  
Ian A Boussy ◽  
Margaret G Kidwell
Keyword(s):  
Drosophila Melanogaster ◽  
Gonadal Dysgenesis ◽  
East Coast ◽  
New South ◽  
Hybrid Dysgenesis ◽  
Latitudinal Cline ◽  
Sharp Drop ◽  
Smooth Tests ◽  
South Wales ◽  
Two Populations

ABSTRACT The dramatic latitudinal cline in P-M hybrid dysgenesis characteristics along the east coast of Australia is not smooth. Tests of recent collections of Drosophila melanogaster from the southeastern coast define the previously described cline as comprising three discrete, apparently contiguous regions of P, Q and M phenotypes, respectively. Northern populations from Cairns (16.9°SLat) to Ourimbah (33.4°SLat) are phenotypically P; populations from Wollongong (34.4°SLat) to Eden (37.1°SLat) are Q; and populations from Genoa (37.5°SLat) to Cygnet (43.2°SLat) are M. The decline in P activity from northern Queensland (55-60% gonadal dysgenesis (GD) in cross A) to mid-New South Wales (20-30% GD in cross A) is gradual; proceeding south, there then is a sharp drop to Q populations (<10% GD in crosses A and A*). This drop in P activity occurs in only 150 km, across the urban and suburban area of Sydney. Q populations are then found south to Eden, but Genoa, only about 50 km further southeast, is clearly M (48% GD in cross A*), as are two populations further south. The two discontinuities in the P-M cline do not correspond to obvious climatic differences along the coast, nor to obvious barriers to dispersal of D. melanogaster. The cline has apparently not moved between 1983 and 1985-1986.

V.—Notes on the ‘Prison of Saint Catharine’ at Salamis in Cyprus

Archaeologia ◽  
1915 ◽  
Vol 66 ◽  
pp. 179-194 ◽  
Author(s):  
John L. Myres
Keyword(s):  
East Coast ◽  
Ground Level ◽  
West Wall ◽  
Outer Chamber ◽  
The North ◽  
Gable Roof ◽  
Single Block ◽  
North Wall ◽  
Ancient Monument ◽  
North And South

The ‘Prison of Saint Catharine’ is an ancient monument on the outskirts of the ruins of Salamis, on the east coast of Cyprus. It consists of two chambers, of which the inner, rectangular with gable roof east-to-west and door at one end, is cut out of a single block of limestone, and roofed with another, which projects slightly above the modern surface of the ground. The junction of the two blocks is about half-way up the gable roof. The outer chamber is much larger and lies transversely to the inner, with its long axis north and south, and the inner chamber door in the middle of its west wall. Nearly opposite in the east wall is the outer entrance, approached from ground-level by a descent of rough steps, between walls of large squared masonry, now much damaged. The walls of the outer chamber consist of enormous upright slabs, crowned by a massive cornice, of a wide cavetto between two fillets, of which the upper projects considerably beyond the lower. On this cornice rests a semicircular vault of very large stones, the largest of which are set on end and occupy as much as a third of the vault. Within, they are carefully dressed, like the wall surfaces, but outside they were left rough, and have suffered further damage from exposure. They were not, however, intended to be seen, for there are remains of an outer casing of massive squared masonry, consisting of a cornice below, of the same profile as that of the vaulted chamber; and over this a plinth of three courses, the upper and lower plain, the middle bearing a simple cyma moulding, convex above. One course of the wall face is traceable still above the plinth, about half-way up the vault. The ends of the vault above the cornice are filled with rough walling, mostly recent, but including a number of stones from the plinth. A breach in the north wall serves as an entrance now, with a modern flight of steps. The building is now buried up to the level of the cornice and the great roof-slab, in a low mound; but the natural ground-level is only about a metre lower.

scholarly journals Intra-Specific Venom Variation in the Australian Coastal Taipan Oxyuranus scutellatus

Toxins ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 485 ◽  
Author(s):  
Theo Tasoulis ◽  
Anjana Silva ◽  
Punnam Chander Veerati ◽  
Mark Baker ◽  
Wayne C. Hodgson ◽  
...  
Keyword(s):  
Sexual Dimorphism ◽  
Snake Venom ◽  
Geographical Variation ◽  
East Coast ◽  
Population Variation ◽  
The Other ◽  
North East ◽  
The North ◽  
Specific Variation ◽  
Two Populations

Intra-specific venom variation has the potential to provide important insights into the evolution of snake venom, but remains a relatively neglected aspect of snake venom studies. We investigated the venom from 13 individual coastal taipans Oxyuranus scutellatus from four localities on the north-east coast of Australia, spanning a distance of 2000 km. The intra-specific variation in taipan venom was considerably less than the inter-specific variation between it and the other Australian elapids to which it was compared. The electrophoretic venom profile of O. scutellatus was visually different to six other genera of Australian elapids, but not to its congener inland taipan O. microlepidotus. There was minimal geographical variation in taipan venom, as the intra-population variation exceeded the inter-population variation for enzymatic activity, procoagulant activity, and the abundance of neurotoxins. The pre-synaptic neurotoxin (taipoxin) was more abundant than the post-synaptic neurotoxins (3FTx), with a median of 11.0% (interquartile range (IQR): 9.7% to 18.3%; range: 6.7% to 23.6%) vs. a median of 3.4% (IQR: 0.4% to 6.7%; range: 0% to 8.1%). Three taipan individuals almost completely lacked post-synaptic neurotoxins, which was not associated with geography and occurred within two populations. We found no evidence of sexual dimorphism in taipan venom. Our study provides a basis for evaluating the significance of intra-specific venom variation within a phylogenetic context by comparing it to the inter-specific and inter-generic variation. The considerable intra-population variation we observed supports the use of several unpooled individuals from each population when making inter-specific comparisons.

scholarly journals White clover: loss in drought and subsequent recovery

2003 ◽  
Vol 11 ◽  
pp. 37-41
Author(s):  
I.M. Knowles ◽  
T.J. Fraser ◽  
M.J. Daly
Keyword(s):  
Population Dynamics ◽  
White Clover ◽  
Tall Fescue ◽  
Trifolium Repens ◽  
East Coast ◽  
Drought Period ◽  
Subsequent Recovery ◽  
The North ◽  
Rate Of Recovery

There are limitations to the production and persistence of white clover in drought prone regions. We report on the population dynamics of white clover during the summer/autumn drought of 2000. Seventeen paddocks were selected from Marlborough, Mid Canterbury, South Canterbury and North Otago on the east coast of the South Island, and Wairarapa in the North Island. The pastures were sown in 1998/99 and are comprised of ryegrass, tall fescue, cocksfoot or combinations of these as the grass base, with white clover included in the mix. White clover populations were monitored pre- and post-drought using tiller cores. The percentage of each region's long-term mean rainfall received during the 6-month "drought period" had the largest influence on the presence of white clover in these pastures. Marlborough, with only 73 mm of rainfall during November 2000-April 2001 (23% of its expected rainfall) suffered a 95% reduction in white clover. Mid Canterbury, South Canterbury and North Otago, at 53-61% of expected rainfall had a 40-78% loss. In contrast, Wairarapa, with 303 mm of rainfall, lost only 8%. The rate of recovery was closely related to the magnitude of white clover loss during drought. In regions where large losses occurred, further sampling after 18 months showed little increase in white clover presence. Key words: drought, persistence, populations, seedling, Trifolium repens, white clover

VIII.—Notes on the Pre-Glacial Rock-Platform on the Wexford Coast

1909 ◽  
Vol 6 (11) ◽  
pp. 507-508
Author(s):  
F. R. Cowper Reed
Keyword(s):  
Solid Rock ◽  
East Coast ◽  
Sand Dunes ◽  
Marine Terrace ◽  
The South ◽  
The North ◽  
The Subject ◽  
The Village ◽  
Nearly Continuous ◽  
North And South

The occurrence of a pre-Glacial marine terrace and raised beach along the coast of the south of Ireland was described by Messrs. Wright & Muff in 1904, and its development in the eastern part of co. Waterford was the subject of two short papers by the author in 1907 in this Magazine. Messrs. Wright & Muff (op. cit.) observed the same raised beach only in the south-eastern portion of co. Wexford, so that its recognition this summer by the author further north along the east coast of Ireland deserves recording, for it has been traced for several miles to the north and south of Courtown Harbour, and its height, characters, and relations to the overlying deposits show that it is a continuation of the same feature. The first locality to be mentioned is about 3 miles to the south of the village of Courtown, where relics of it are preserved between Roney Point and Salt Rock; it is still more distinct as a rock-terrace a little further north at Pollshone Head and Breanoge Head, but in the bays between these points the conditions are not favourable for its exposure, as there are no rocky cliffs, only extensive sand-dunes stretching along the shore. From Courtown Harbour northwards for about 2 miles to Duffcarrig Rocks sand-dunes are similarly developed, forming a nearly continuous line of ridges rising to heights of over 50 feet. Thick drift deposits occur behind them, but no pre-Glacial cliff or platform is exposed. At Duffcarrig Rocks solid rock again appears forming the headland, and we can recognize remnants of the rock-cut shelf in a much eroded and fissured condition.

scholarly journals Comparison of the Sex Pheromone Composition of Harmonia axyridis Originating from Native and Invaded Areas

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 326 ◽  
Author(s):  
Legrand ◽  
Vanderplanck ◽  
Verheggen
Keyword(s):  
Sex Pheromone ◽  
Harmonia Axyridis ◽  
The North ◽  
Asian Lady Beetle ◽  
Pheromone Composition ◽  
Multicolored Asian Lady Beetle ◽  
Strain Release ◽  
North And South America ◽  
North And South ◽  
Two Populations

The multicolored Asian lady beetle, Harmonia axyridis (Coleoptera: Coccinellidae), originates from South-East Asia and is now considered as an invasive species at a worldwide scale, with populations encountered in North and South America, Africa, and Europe. Several previous studies suggested that invasive populations display different behavioral and physiological traits, leading to a better fitness than native individuals. H. axyridis sex pheromone was identified recently, but only from individuals established in Europe. In this study, we compare the composition of the female sex pheromone of H. axyridis from two populations: (i) an invasive population in North America, and (ii) a native population in South-East China. We found the females originating from both populations to release in similar proportions the same five pheromonal compounds, namely β-caryophyllene, β-elemene, methyl-eugenol, α-humulene, and α-bulnesene. However, females from the North American strain release all five compounds in larger amount than the Chinese ones. Whether invasive individuals were selected during the process of invasion through their capacity to better call and find sexual partners remains to be confirmed.

scholarly journals Vorticity Structures in the Tropical Pacific from a Numerical Simulation

2011 ◽  
Vol 41 (8) ◽  
pp. 1455-1464 ◽  
Author(s):  
Clement Ubelmann ◽  
Lee-Lueng Fu
Keyword(s):  
Rossby Waves ◽  
Tropical Pacific ◽  
Small Scale ◽  
Coriolis Parameter ◽  
Structure Characteristics ◽  
The North ◽  
Spatially Inhomogeneous ◽  
Different Characteristics ◽  
North And South ◽  
The Tropical Pacific

Abstract The small-scale variability of the tropical Pacific is studied with the simulations from a numerical model in terms of vorticity structures. A Lagrangian method based on the Okubo–Weiss parameter is used to identify the structures and track their main characteristics. Between 8°S and 8°N, the structure characteristics are spatially inhomogeneous compared to higher latitudes. They can be grouped into three categories: anticyclonic and cyclonic structures off the equator and the equatorial structures between 2°S and 2°N. They all have a strong annual cycle with maximum presence from September to March, except during strong El Niño years, when the number of structures becomes very low. Off the equator from 2° to 8°, the anticyclonic structures dominate, but with drastically different characteristics north and south of the equator. In the north, large nonlinear vortices develop (known as the tropical instability vortices) in phase with the 30–35-day oscillation related to an unstable first-meridional-mode Rossby waves. In the south, mostly fragmentary linear structures are present, with lower propagation speeds. The equatorial structures are mostly counterclockwise. The larger ones tend to be linear and are clearly associated with Yanai waves. The large majority of the cyclonic structures off the equator are also quite linear and smaller and less numerous than the anticyclonic structures. However, some of them are nonlinear with vorticity values higher than 2 times the Coriolis parameter.

Genetic differentiation and inversion clines in Indian natural populations of Drosophila melanogaster

Genome ◽  
1991 ◽  
Vol 34 (4) ◽  
pp. 618-625 ◽  
Author(s):  
Aparup Das ◽  
B. N. Singh
Keyword(s):  
Drosophila Melanogaster ◽  
Genetic Differentiation ◽  
Natural Populations ◽  
The South ◽  
The North ◽  
Chromosome Inversions ◽  
The Difference ◽  
And Inversion ◽  
First Time ◽  
North And South

To study the genetic differentiation and inversion clines in Indian natural populations of Drosophila melanogaster, 14 natural populations (6 from the north and 8 from the south) were screened for chromosome inversions. The chromosomal analysis revealed the presence of 23 paracentric inversions, which include 4 common cosmopolitan, 4 rare cosmopolitan, 2 recurrent endemic, and 13 unique endemic (new inversions detected for the first time) inversions. The difference in karyotype frequencies between populations from the north and south were highly significant and the level of inversion heterozygosity was higher in populations from the south. Statistically significant negative correlations were found between each of the four common cosmopolitan inversions and latitude. These findings are in accord with results from other worldwide geographic regions and show that Indian populations of D. melanogaster have undergone considerable genetic differentiation at the level of inversion polymorphism.Key words: Drosophila melanogaster, Indian natural populations, chromosome inversions, genetic differentiation, north–south clines.

scholarly journals Nitrogen use and farm performance on Wairarapa sheep and beef farms

1993 ◽  
pp. 53-57
Author(s):  
J.D. Morton ◽  
C.J. Korte ◽  
D.R. Smith ◽  
B.D. Watt ◽  
R.G. Smith
Keyword(s):  
Financial Performance ◽  
East Coast ◽  
Perennial Grasses ◽  
Factors Affecting ◽  
Annual Legumes ◽  
The North ◽  
Winter Grazing ◽  
Major Factors ◽  
North And South ◽  
N Use

Seventy-eight sheep and beef farms on the east coast of the North and South Islands were surveyed in August/September 1991 on the use and benefits of nitrogen (N) fertiliser. The survey covered the years 1987/88-1990/91 and included 16 sheep and beef farms in Wairarapa. Farms with high N use (>5 kg/ha/year on average over the whole farm area in pasture and crop) received 20 (Wairarapa) or 28 (other east coast regions) kgN/ ha/year on 83 or 53% of the farm area respectively. Diammonium phosphate (DAP) was the major form of N used in Wairarapa. Urea and DAP/ammonium sulphate mixes were the major forms used in other east coast regions. Most of the N was applied from May to August in all regions. High use of DAP in Wairarapa was associated with higher rates of phosphorus but lower rates of sulphur applied compared with other regions. Survey farmers identified feed demand as the major factor influencing amount of N applied and the timing of application. Soil moisture and temperature at application were ranked as the major factors affecting the response to N. Benefits of N were listed as lower susceptibility to drought, higher calf weaning weights, longer winter grazing rotation and greater pasture cover at lambing. Over the whole survey, N use was associated with significantly higher animal and financial performance. N use on easy land on the North Island survey farms was associated with a significantly lower presence of browntop, other perennial grasses (mainly Yorkshire fog and crested dogstail), white clover, annual legumes (mainly suckling and cluster clover) and flatweeds. On steep hills, N use was associated with a significantly lower presence of other perennial grasses and annual legumes. Keywords: animal performance, financial performance, nitrogen fertiliser, pasture species, sheep and beef farms

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