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Key message The study unraveled the dynamics of mechanisms causing biennality in coffee, its consequences for competition for carbon and nitrogen and suggests means of adequately managing the problem. Imbalance in fruit load and branch growth plays a role in the occurrence of biennial bean production patterns in coffee ( Coffea arabica L.). Effects of fruit load manipulations were studied in two field experiments in the Jimma region, Ethiopia, over two consecutive years. Treatments consisted of reducing fruit loads in the pinhead stage to 25, 50, 75 % and controls keeping 100 % of the fruits per tree (treatments coded T25 through T100). Treatments were applied in the first year only. Branch growth and the formation of new leaves, drop of old leaves, light saturated rate of leaf photosynthesis ( A max ), nitrogen content of leaves on selected branches, as well yield and bean characteristics were evaluated throughout the experimental period. The study revealed that branch growth, and leaf N content per unit leaf area, N a , were inversely associated with fruit load, whereas loss of basal leaves on branches increased with fruit load and over time. A max was strongly and linearly associated with N a and declined with increase in fruit load. In the year of treatment green bean yield increased with fruit load, but in the second year the reverse was true. On aggregate over 2 years, treatment T25 and T50 out yielded treatments T75 and T100. Fruit thinning shifted the bean size distribution to larger sizes. In conclusion, fruit thinning modulated the balance between branch growth and fruit development. Thus enhanced branch growth, improved bean size and stabilized yield over years.

Left–right (L-R) asymmetry of the internal organs of vertebrates is presaged by domains of asymmetric gene expression in the lateral plate mesoderm (LPM) during somitogenesis. Ciliated L-R coordinators (LRCs) are critical for biasing the initiation of asymmetrically expressed genes, such as nodal and pitx2, to the left LPM. Other midline structures, including the notochord and floorplate, are then required to maintain these asymmetries. Here we report an unexpected role for the zebrafish EGF-CFC gene one-eyed pinhead (oep) in the midline to promote pitx2 expression in the LPM. Late zygotic oep (LZoep) mutants have strongly reduced or absent pitx2 expression in the LPM, but this expression can be rescued to strong levels by restoring oep in midline structures only. Furthermore, removing midline structures from LZoep embryos can rescue pitx2 expression in the LPM, suggesting the midline is a source of an LPM pitx2 repressor that is itself inhibited by oep. Reducing lefty1 activity in LZoep embryos mimics removal of the midline, implicating lefty1 in the midline-derived repression. Together, this suggests a model where Oep in the midline functions to overcome a midline-derived repressor, involving lefty1, to allow for the expression of left side-specific genes in the LPM. This article is part of the themed issue ‘Provocative questions in left–right asymmetry’.

The sequencing of the zebrafish genome should be completed by the end of 2002. Direct assignment of function on the basis of this information would be facilitated by the development of a rapid, targeted ‘knockdown’ technology in this model vertebrate. We show here that antisense, morpholino-modified oligonucleotides 1 (morpholinos) are effective and specific translational inhibitors in zebrafish. We generated phenocopies of mutations of the genes no tail (ref. 2 ), chordin (ref. 3 ), one-eyed-pinhead (ref. 4 ), nacre (ref. 5 ) and sparse (ref. 6 ), removing gene function from maternal through post-segmentation and organogenesis developmental stages. We blocked expression from a ubiquitous green fluorescent protein (GFP) transgene, showing that, unlike tissue-restricted limitations found with RNA-based interference in the nematode 7 , all zebrafish cells readily respond to this technique. We also developed also morpholino-based zebrafish models of human disease. Morpholinos targeted to the uroporphyrinogen decarboxylase gene 8 result in embryos with hepatoerythropoietic porphyria. We also used morpholinos for the determination of new gene functions. We showed that embryos with reduced sonic hedgehog (ref. 9 ) signalling and reduced tiggy-winkle hedgehog (ref. 10 ) function exhibit partial cyclopia and other specific midline abnormalities, providing a zebrafish genetic model for the common human disorder holoprosencephaly. Conserved vertebrate processes and diseases are now amenable to a systematic, in vivo , reverse-genetic paradigm using zebrafish embryos.

This study aimed to assess and compare the behavior of superior genotypes of Coffea canephora in terms of fruiting capacity using directed hybridizations in a full diallel design with reciprocals. Hybridizations were performed using 12 possible combinations between genotypes 02, 03, 23 and 83 from the Incaper breeding program. High estimates of the genotypic coefficient of determination in terms of the total number of pinheads per cross (TNP) and fruit set (FS) indicated variability of genetic nature. FS averaged 52,27 %, ranging from 31,32 % to 82,09 %, with the higher rates relating to clone 23 as the male parent. Differences were found between reciprocal crosses in the combinations with genotype 23, which emerged as the donor plant with the best fruiting rate, but poor receiving ability. Clone 83 prevailed as the best receiving plant and the least effective donor. In the comparison of these two genotypes, antagonism was observed in their behavior when they were used as pollen-donor plants (male parents) and pollen-receiver plants (female parents), highlighting their possible maternal effect. Crosses involving clones 02 and 03 showed no differences when used reciprocally. The estimates of genotypic correlations were negative for the four associations involving the FS characteristic, being of greater magnitude with TNP. Este trabajo tuvo como objetivo evaluar y comparar la eficiencia en la producción de frutos entre cruces recíprocos en Coffea canephora con el uso de hibridaciones controladas en un dialelo completo con diseño recíproco. Las hibridaciones se realizaron involucrando los genotipos 02, 03, 23 y 83 del programa de mejoramiento Incaper. Las estimaciones altas del coeficiente de determinación genotípica para el número total de frutos iniciados por cruzamiento (TNP) y la proporción de frutos (FS) indicaron una variabilidad de naturaleza genética. La FS promedio fue de 52,27 %, con un rango de 31,32 % a 82,09 %, siendo mayor con el clon 23 como progenitor masculino. Se encontraron diferencias entre cruces recíprocos en combinaciones con el genotipo 23, que se destacó como la planta donante con la mejor tasa en la producción de frutos, pero con habilidad receptora deficiente. El clon 83 se destacó como la mejor planta receptora y la peor donante. En la comparación de estos dos genotipos (23 y 83) se observó antagonismo en su comportamiento al ser utilizados como plantas donadoras de polen (progenitores masculinos) y plantas receptoras de polen (progenitores femeninos), evidenciando un posible efecto maternal. Los cruces entre los clones 02 y 03 no mostraron diferencias cuando se usaron recíprocamente. Las estimaciones de las correlaciones genotípicas fueron negativas para las asociaciones que involucraron la característica FS, siendo de mayor magnitud con TNP.

Pleurotus (Oyster mushroom) is an important cultivated edible mushroom across the world. It has several therapeutic effects as it contains various useful bio-molecules. The cultivation and crop management of these basidiomycete fungi depends on many extrinsic and intrinsic factors such as substrate composition, growing environment, enzymatic properties, and the genetic makeup, etc. Moreover, for efficient crop production, a comprehensive understanding of the fundamental properties viz. intrinsic–extrinsic factors and genotype-environment interaction analysis is required. The present study explores the basidiocarp formation biology in Pleurotus mushroom using an in silico response to the environmental factors and involvement of the major regulatory genes. The predictive model developed in this study indicates involvement of the key regulatory pathways in the pinhead to fruit body development process. Notably, the major regulatory pathways involved in the conversion of mycelium aggregation to pinhead formation and White Collar protein (PoWC1) binding flavin-chromophore (FAD) to activate respiratory enzymes. Overall, cell differentiation and higher expression of respiratory enzymes are the two important steps for basidiocarp formation. PoWC1 and pofst genes were participate in the structural changes process. Besides this, the PoWC1 gene is also involved in the respiratory requirement, while the OLYA6 gene is the triggering point of fruiting. The findings of the present study could be utilized to understand the detailed mechanism associated with the basidiocarp formation and to cultivate mushrooms at a sustainable level.

Holoprosencephaly (HPE) is the most common structural defect of the developing forebrain in humans (1 in 250 conceptuses, 1 in 16,000 live-born infants 1 , 2 , 3 ). HPE is aetiologically heterogeneous, with both environmental and genetic causes 4 , 5 . So far, three human HPE genes are known: SHH at chromosome region 7q36 (ref. 6 ); ZIC2 at 13q32 (ref. 7 ); and SIX3 at 2p21 (ref. 8 ). In animal models, genes in the Nodal signalling pathway, such as those mutated in the zebrafish mutants cyclops (refs 9 , 10 ), squint (ref. 11 ) and one-eyed pinhead ( oep ; ref. 12 ), cause HPE. Mice heterozygous for null alleles of both Nodal and Smad2 have cyclopia 13 . Here we describe the involvement of the TG-interacting factor (TGIF), a homeodomain protein, in human HPE. We mapped TGIF to the HPE minimal critical region in 18p11.3. Heterozygous mutations in individuals with HPE affect the transcriptional repression domain of TGIF, the DNA-binding domain or the domain that interacts with SMAD2. (The latter is an effector in the signalling pathway of the neural axis developmental factor NODAL, a member of the transforming growth factor-β (TGF-β) family.) Several of these mutations cause a loss of TGIF function. Thus, TGIF links the NODAL signalling pathway to the bifurcation of the human forebrain and the establishment of ventral midline structures.

Mutant analysis in the zebrafish Danio rerio has demonstrated distinct developmental roles for the T-box transcription factor Spadetail (Spt) 1 and the Nodal-receptor cofactor One-Eyed Pinhead (Oep) 2 in the formation of mesoderm and endoderm. Here, we show that spt and oep genetically interact and are together essential for the formation of cardiac and somitic mesoderm. These two mesodermal defects are dependent on different effectors of Nodal signalling; cardiac mesoderm formation involves the mix -like transcription factor Bonnie and Clyde (Bon) 3 , whereas somitogenesis is dependent on a different pathway. Analysis of the somite defect in Zoep;spt embryos has provided insights into the control of somitic mesoderm formation by Spt, which was previously implicated in the regulation of cell adhesion and motility 4 , 5 . We show that the failure to form somites in Zoep;spt embryos is independent of this and that Spt must have an additional function. We propose that the major role of Spt in somitogenesis is to promote the differentiation of presomitic mesoderm from tailbud progenitors by antagonizing progenitor-type gene expression and behaviour.

Pinhead and I go back a long way. He is a good mate, my best mate within the refereeing ranks. In recent years [Pinhead] has become a fully-fledged religious minister, but has still retained his larrikin nature. All I can say is that Pinhead was dealt an injustice. He has been the game's best referee over the past two years and should have been given the nod for Origin.

Victoria was having one of those terrific winter gales spawned at sea, with winds gusting to 120 kilometres an hour. [Johnny \"Pinhead\" McLean] knew I had just bought a 1930 Essex from Smiling Ben's used car lot on lower Douglas, and he prevailed upon me to drive my pride and joy into a raging gale -- the kind of storm that in prior years had washed a casket from its resting place in the cemetery. When we arrived at the site, the wind was howling like a banshee - - waves were towering over the concrete railing and breaking onto the tombstones. We drove around the traffic barricade (after all, I was ferrying a reporter on assignment). Johnny's original intention had been to stand on the roof of the car and photograph a monstrous wave as it crashed towards him. I don't think Johnny could have been listening. Questions were just getting under way when he interrupted and asked the admiral if he would be good enough to pose for a photograph \"by that stuffed crow.\" What Johnny didn't know was that the admiral was an internationally recgonized ornithologist, and the \"stuffed crow\" was an outstanding example of an endangered species from the jungles of Venezuela.