In anthers, the tapetum synthesizes and stores proteins and flavonoids, which will be transferred to the surface of adjacent microspores. The mechanism of synthesis, storage, and transfer of these pollen-coat materials in maize (Zea mays) differs completely from that reported in Arabidopsis (Arabidopsis thaliana), which stores major pollen-coat materials in tapetosomes and elaioplasts. On maize...

Male fertility in flowering plants depends on proper cellular differentiation in anthers. Meiosis and tapetum development are particularly important processes in pollen production. In this study, we showed that the tomato male sterile (ms10(35)) mutant of cultivated tomato (Solanum lycopersicum) exhibited dysfunctional meiosis and an abnormal tapetum during anther development, resulting in no p...

BACKGROUND AND AIMS Although orbicular functions are still a matter of debate, they are considered by most authors to be exclusively formed by a secretory tapetum. However, the presence of orbicules on a peritapetal membrane associated with a plasmodial tapetum has been described for Abutilon pictum (Malvaceae) in a previous study. Thus, studies on other species of Malvaceae are necessary to co...

The structure of the canine tapetum lucidum appears to be basically similar to that described in some other carnivores, but specific distinctions are present. The reflecting rodlets of the dog are similar in their dimensions to those of the cat, but they are more closely packed, resulting in a unique value for the wavelength of maximal reflectance. In addition, the rodlets are less precisely or...

This paper describes the cytochemistry and ultrastructure of the developing tapetum in Primula obconica, a plant with a heteromorphic, sporophytic self-incompatibility system. The tapetum is of the secretory type and cytochemical tests have shown that when it breaks down proteinaceous (esterase) and lipidic components are deposited on the developing pollen grains. Acid phosphatase, a marker of ...

In flowering plants, the tapetum, the innermost layer of the anther, provides both nutrient and lipid components to developing microspores, pollen grains, and the pollen coat. Though the programmed cell death of the tapetum is one of the most critical and sensitive steps for fertility and is affected by various environmental stresses, its regulatory mechanisms remain mostly unknown. Here we sho...

The development of preparation techniques that include freeze fracturing provide an ideal method for studying the differentiation of plant tissues in the scanning electron microscope. This is illustrated with reference to tapetal development in Catananche caerulea, which has a plasmodial tapetum, and in Lolium perenne, which has a secretory tapetum.

The pollen wall, an essential structure for pollen function, consists of two layers, an inner intine and an outer exine. The latter is further divided into sexine and nexine. Many genes involved in sexine development have been reported, in which the MYB transcription factor Male Sterile 188 (MS188) specifies sexine in Arabidopsis. However, nexine formation remains poorly understood. Here we rep...

The ocelli of Archaeognatha, or jumping bristletails, differ from typical insect ocelli in shape and field of view. Although the shape of the lateral ocelli is highly variable among species, most Machiloidea have sole-shaped lateral ocelli beneath the compound eyes and a median ocellus that is oriented downward. This study investigated morphological and physiological aspects of the ocelli of Ma...

Important phenomena related to rice, such as Cytoplasmic male sterility (CMS), self-incompatibility and sex determination, are involved in sexual reproduction. For rice, the development process of male gametophyte and pollen contains several stages, including pre-meiotic anther (PMA), meiosis (MEI), tetrad (TET), uninuclear (UN) microspore, bicellular (BC) pollen, tricellular (TC) pollen, MEI, ...