Summer pruning effects in apple — a review

Summer pruning effects in apple have generally been attributed to improved light penetration and to reduced carbohydrate supply. However, the common basis to most of these effects seems to be the retardation of senescence, a process under hormonal control. Summer pruning causes a temporary loss of apical dominance except when thinning cuts are used. It also causes a temporary increase in cytokinin supply, presumably mainly by increased export from the roots. Both effects presumably result from reduced auxin availability.

Depending on its timing, the resulting rejuvenation may consist of mobilization and redistribution of nutrients and phytohormones, breaking of axillary buds, inhibition of flower induction, delayed fruit development and later induction of dormancy. The extent of pruning responses increases with the vigour of the tree, the earliness of pruning and its severity. Heading and stubbing are more effective in provoking these responses than thinning of shoots. In areas with a short season, summer pruning may not only delay, but also prevent, the onset of dormancy, with adverse effects on winter hardiness. The mostly positive influence of summer pruning on fruit colour by factors in addition to better light penetration is discussed. Summer pruning, where considered necessary, needs to be adjusted to local conditions and coordinated with other cultural practices.     

The bovine innate immune response during experimentally-induced Pseudomonas aeruginosa mastitis

Almost half of all clinical cases of mastitis are caused by Gram-negative bacteria. Among these bacteria, intramammary infection by Pseudomonas aeruginosa remains one of the most refractory to antibiotic therapy. The ability to recognize potentially harmful pathogens whether previously encountered or not, as well as the induction of an initial pro-inflammatory response to these pathogens, are critical components of host innate immunity. Although the innate immune response to another Gram-negative mastitis-causing pathogen, Escherichia coli, has been well-characterized, little is known about the response to other Gram-negative bacteria, including P. aeruginosa. The objective of the current study was to characterize the systemic and localized bovine innate immune response to intramammary infection with P. aeruginosa. The contralateral quarters of ten mid-lactating Holstein cows were challenged with either saline or P. aeruginosa. Following the establishment of infection, milk samples were collected and assayed for changes in cytokine and growth factor concentrations, complement activation, and changes in the levels of soluble CD14 (sCD14) and lipopolysaccharide (LPS)-binding protein (LBP), two accessory molecules involved in host recognition of Gram-negative bacteria. Initial increases in milk somatic cell counts were evident within 12h of experimental challenge and remained elevated for >or=3 weeks. Increased permeability of the mammary gland vasculature, as evidenced by elevated milk levels of BSA, was initially observed 20 h post-infection and persisted for 2 weeks. Within 32 h of challenge, increased levels of IL-8, TNF-alpha, IL-10, and IL-12 were detected, however, the elevated levels of these cytokines were not sustained for longer than a 24h period. In contrast, elevations in IL-1beta, IFN-gamma, TGF-alpha, TGF-beta1, TGF-beta2, sCD14, LBP, and activated complement factor 5 (C5a) were sustained for periods of >48 h. Systemic changes were characterized by elevated body temperature, induction of the acute phase protein synthesis of serum amyloid A and LBP, and a transient decrease in circulating neutrophils and lymphocytes. Together, these data demonstrate the capability of the mammary gland to mount a robust innate immune response to P. aeruginosa that is characterized by the induction of pro-inflammatory cytokines, complement activation, and increased levels of accessory molecules involved in Gram-negative bacterial recognition.     

The application of sexual coral recruits for the sustainable management of ex situ populations in public aquariums to promote coral reef conservation — SECORE Project

• 1. SECORE (SExual COral REproduction) Project is an initiative of public aquariums and research institutions to produce and exchange sexual coral recruits for the sustainable management of ex situ populations. Here we present the results of the initial three years (2002–2004).
• 2. Primary polyps (n=501) of corals (Acropora tenuis, Agaricia humilis, Favia fragum) were transported from Rotterdam Zoo to Cologne, Burgers', Hagenbeck and London Zoos, where development of juveniles was monitored for 10 months. All polyps were produced at Rotterdam Zoo from laboratory colonies (A. humilis, F. fragum), and from larvae generated from field collected gametes at Akajima, Okinawa, Japan (A. tenuis). Additionally, planulae of A. tenuis (n=1440) were transported from Rotterdam Zoo to Burgers' Zoo and to London Zoo to obtain primary polyps.
• 3. Larval settlement (A. tenuis) was observed to be 3.00 ± 2.57% (mean ± SD; n=1480) in 2002 and 17.36 ± 6.01% (mean ± SD; n=1480) in 2003, significantly lower compared to settlement at Rotterdam Zoo (57.84 ± 11.01% in 2003; mean ± SD, n=1480). High post‐transport survival rates of 95.18 ± 4.86% (mean ± SD; n=501) were observed in primary polyps of all species.
• 4. Juvenile survival (t=10 months; A. tenuis: 18.4–86.2%; A. humilis: 0–19.7%; F. fragum: 13.3–72.7%) differed significantly between institutions. Mean colony sizes (measured 10 months after transportation) were, in all cases, similar or higher to those reported from literature.
• 5. The results demonstrate the potential of this method to serve as an economical and sustainable alternative to existing mostly exploitative techniques for aquarium stocking. The use of sexual recruits provides an effective and low cost alternative, which is, in principle, applicable to all coral species.
• 6. The project was extended from 9 to 28 institutions across Europe, the USA and Japan in 2004.

Copyright © 2006 John Wiley & Sons, Ltd.     

78,XX testicular DSD syndrome in a mongrel dog

Because of an apparent sexual ambiguity (enlarged clitoris), a 1-year-old mongrel dog was presented to the clinic. A positive result on a GnRH stimulation test revealed the existence of functional testicular tissue. A midline laparotomy was performed, and gonads resembling testes were resected along with the adherent parts of the uterine horns. Microscopic examination confirmed that the sampled gonads were testes. Cross-sections of the head and tail of the epididymis revealed their typical structures. All layers of the uterine wall were well-developed. The lumen was stellar, covered by columnar cylindrical epithelium, although locally some epithelial cells had changed in height from columnar to flat. The uterine glands were distributed in functional layer of endometrium in a non-uniform way. Cytogenetic analysis based on the evaluation of metaphase plates of blood lymphocytes showed a female karyotype, 78,XX. PCR amplification of the SRY gene was negative in the studied mongrel dog. This canine disorder may be genetically heterogeneous, potentially with a different mutation in different breeds. An autosomal recessive inheritance for the XX male is suggested in such cases. The present case of sex reversal syndrome concerns a non-purebred dog. In mongrels, it is definitely less likely for the defect to be inherited because of a recessive disorder. According to the recently proposed nomenclature, the described case should be classified as 78,XX testicular DSD syndrome.     

DNA育种对养猪业的贡献

猪育种专家和生产者可做的工作决不仅仅是给猪称重,而是从较大窝重中选择后备母猪和选择生长最快的猪或有价值的猪。分子图谱(DNA)分析对猪遗传育种专家如何选择目前商品猪群中遗传的差异具有划时代的影响。过去10年中,猪遗传育种专家第一次直接研究了猪的染色体图谱,包括自由遗传标记和已经知道的基因。就像交通地图一样,在这些图谱上,研究者可以分析和找到影响猪主要经济性状的染色体区域和主要的基因。这些研究已经以遗传检测(DNA)的形式产生了真正的成果,该检测对个体生产者和育种公司改善种群具有重要作用。在养猪行业中,可以采用大…