Arabidopsis ROP‐interactive CRIB motif‐containing protein 1 (RIC1) positively regulates auxin signalling and negatively regulates abscisic acid (ABA) signalling during root development

Auxin and abscisic acid (ABA) modulate numerous aspects of plant development together, mostly in opposite directions, suggesting that extensive crosstalk occurs between the signalling pathways of the two hormones. However, little is known about the nature of this crosstalk. We demonstrate that ROP‐interactive CRIB motif‐containing protein 1 (RIC1) is involved in the interaction between auxin‐ and ABA‐regulated root growth and lateral root formation. RIC1 expression is highly induced by both hormones, and expressed in the roots of young seedlings. Whereas auxin‐responsive gene induction and the effect of auxin on root growth and lateral root formation were suppressed in the ric1 knockout, ABA‐responsive gene induction and the effect of ABA on seed germination, root growth and lateral root formation were potentiated. Thus, RIC1 positively regulates auxin responses, but negatively regulates ABA responses. Together, our results suggest that RIC1 is a component of the intricate signalling network that underlies auxin and ABA crosstalk.     

Further studies on the occurrence of freshwater Microturbellaria in the British Isles

Macrostomwn johni sp. nov. from Llyn Cwellyn, N. Wales is described. The species has been recorded from the vegetational littoral in December and February only. The main distinguishing criterion is the penis stylet which consists of a funnel, about 80-98 μm in length in slightly squashed specimens, curved in two planes and with a sub-terminal distal opening, the distal end is blunt and cowl (hood) shaped. Other features include the presence of sensory hairs and rhabdoids all over the body, ‘Haft-papillen’, and eyes. Rhammite tracks are weakly developed. The testes are elongate and the ovaries are compact, though slightly indented, and smaller than the testes. A very short ductus intervesicularis is present. The vagina is short. A ‘Verschlussap-parat’ is present but poorly developed.     

Fine needle aspiration cytology in the work-up of mammographic and ultrasonographic findings in breast cancer screening: an attempt at differentiating in situ and invasive carcinoma.

This study evaluated the results of fine needle aspiration cytology (FNAC) from the first four years of organized mammography screening for breast cancer in Oslo, particularly our policy in differentiating in situ and invasive carcinoma. Lesions were aspirated directly, ultrasound guided, by stereotaxic device or biopsy localization plate. All lesions were aspirated by cytopathologists working with the radiologists at the breast diagnostic centre. Smears were evaluated immediately for assessment of adequacy and a preliminary diagnosis was given to the surgeon. When FNAC revealed malignancy, diagnostic terms were as follows: (1) invasive carcinoma; (2) ductal carcinoma in situ of comedo type (high nuclear grade), cannot evaluate infiltration; (3) ductal carcinoma in situ of low nuclear grade and (4) papillary tumour, cannot evaluate infiltration. There were 953 cases, 70% of which were nonpalpable. Insufficient material was obtained in 5.8%. Absolute and complete sensitivity were 81% and 91%, respectively. Specificity was 85%. There were 448 histologically proven carcinomas. 383 of these were invasive. 362 carcinomas (in situ and invasive) (80.8%) were diagnosed directly on FNAC. Distinction between invasive and in situ carcinoma was possible in 294 of 320 directly diagnosed invasive carcinomas (91.8%). PPV of a diagnosis of invasive carcinoma was 97%. Our data showed that definitive cytological diagnosis of invasive carcinoma was possible in more than 90% of fully diagnostic smears and allowed definitive primary surgery in these women.     

Demographic Sensitivity of Population Change in Northern Bobwhite

Abstract: The northern bobwhite (Colinus virginianus) is an economically important gamebird that is currently undergoing widespread population declines. Despite considerable research on the population ecology of bobwhites, there have been few attempts to model population dynamics of bobwhites to determine the contributions of different demographic parameters to variance of the finite rate of population change (Λ). We conducted a literature review and compiled 405 estimates of 9 demographic parameters from 49 field studies of bobwhites. To identify demographic parameters that might be important for management, we used life-stage simulation analyses (LSA) to examine sensitivity of Λ to simulated variation in 9 demographic parameters for female bobwhites. In a baseline LSA based on uniform distributions bounded by the range of estimates for each demographic parameter, bobwhite populations were predicted to decline (Λ = 0.56) and winter survival of adults made the greatest contribution to variance of Λ (r² = 0.453), followed by summer survival of adults (r² = 0.163), and survival of chicks (r² = 0.120). Population change was not sensitive to total clutch laid, nest survival, egg hatchability, or 3 parameters associated with the number of nesting attempts (r²<0.06). Our conclusions were robust to alternative simulation scenarios, and parameter rankings changed only if we adjusted the lower bounds of winter survival upwards. Bobwhite populations were not viable with survival rates reported from most field studies. Survival rates may be depressed below sustainable levels by environmental conditions or possibly by impacts of capture and telemetry methods. Overall, our simulation results indicate that management practices that improve seasonal survival rates will have the greatest potential benefit for recovery of declining populations of bobwhites.     

Divergence in cuticular hydrocarbons between parapatric subspecies of the meadow grasshopper, Chorthippus parallelus (Orthoptera, Acrididae)

Two subspecies of the grasshopper Chorthippus parallelus (Orthoptera; Acrididae) meet and form a hybrid zone in the Pyrenees. Here we investigate whether the subspecies differ in the blend of cuticular hydrocarbons. Such differences may function as chemical signals, being detected via contact chemoreception and used during mate choice as in other insects. Gas chromatography shows that the subspecies have diverged in the composition of their cuticular hydrocarbons. This difference between subspecies exists over and above variation in cuticular hydrocarbons among individual populations. The majority of the difference can be attributed to the relative amounts of a small group of compounds present in the cuticle. The possible consequences of this chemical divergence for mating encounters between the subspecies are discussed.