Chromosome Elimination En Bloc in Saccharum*
نویسنده
چکیده
Variation in somatic and gametic chromosome numbers in Ribes nipuw (Vaarama 1949) and Eruca sativa (Rajan et al., 1950) has been attributed to the formation of accessory spindle and subsequent "elimination of clzrolnosoines e n bloc". In sugarcane, Parthasarathy (1951)~ after exa~nining the slides of megasporogenesis in Co. 421 prepared by Subrainaniam (1946), concluded that the mechanism of elimination accounts for the anomalous chromosome numbers in certain hybrids. According to him "this kind of abnormality is only characteristic of megaspore mother cells and is not found in the pollen mother cells". Raghavan (1954) recorded "elimination of chromosomes en bloc" through the formation of the accessory spindle during the first meiotic metaphase in the pollen mother cells of S. robustuw. This is not found
منابع مشابه
A comparison of cyst wall curettage and en bloc excision in the treatment of aneurysmal bone cysts
BACKGROUND The recurrence rate after aneurysmal bone cyst (ABC) treatment is quite high despite its benign nature. In ABC therapy, curettage is the treatment of choice; en bloc excision results in a lower recurrence rate, but more extensive reconstructive surgery is needed with associated morbidity. The aim of the present study was to compare the outcomes of the two treatment options. METHODS...
متن کاملSurgical technique of en bloc pelvic resection for advanced ovarian cancer
OBJECTIVE The aim of this paper was to describe the operative details for en bloc removal of the adnexal tumor, uterus, pelvic peritoneum, and rectosigmoid colon with colorectal anastomosis in advanced epithelial ovarian cancer patients with widespread pelvic involvement. METHODS The patient presented with good performance status and huge pelvic tumor extensively infiltrating into adjacent pe...
متن کاملEn bloc ligation of renal vessels is safe and reduces duration of surgery.
INTRODUCTION Conventionally, individual ligation of the renal vessels with clips is performed during laparoscopic nephrectomy (LN). Concomitant ligation of the vessels is not a standard procedure due to an expected risk of stapler dysfunction and the development of arteriovenous fistulas (AVF). Using the EndoGIA stapler 45/2.5 mm, we compared en bloc ligation with individual ligation during LN ...
متن کاملEn Bloc Resection of Solitary Functional Secreting Spinal Metastasis.
Study Design Literature review. Objective Functional secretory tumors metastatic to the spine can secrete hormones, growth factors, peptides, and/or molecules into the systemic circulation that cause distinct syndromes, clinically symptomatic effects, and/or additional morbidity and mortality. En bloc resection has a limited role in metastatic spine disease due to the current paradigm that syst...
متن کاملAltered growth and fine root chemistry of Betula papyrifera and Acer saccharum under elevated CO2
We investigated the effects of CO2 enrichment on fine root chemical composition of two tree species common to northern hardwood forests. Two-year-old Betula papyrifera and 3-year-old Acer saccharum saplings were grown under ambient (400 μmol·mol–1) and elevated (700 μmol·mol–1) CO2 in a glasshouse experiment. In both species, root/shoot ratios and fine root percentages (of total biomass) were u...
متن کامل