Diet-induced obesity is a major risk factor for metabolic syndrome, diabetes and cardiovascular disease. Here, we show that a 5-d fasting-mimicking diet (FMD), administered every 4 weeks for a period of 2 years, ameliorates the detrimental changes caused by consumption of a high-fat, highcalorie diet (HFCD) in female mice. We demonstrate that monthly FMD cycles inhibit HFCDmediated obesity by reducing the accumulation of visceral and subcutaneous fat without causing loss of lean body mass. FMD cycles increase cardiac vascularity and function and resistance to cardiotoxins, prevent HFCD-dependent hyperglycaemia, hypercholesterolaemia and hyperleptinaemia and ameliorate impaired glucose and insulin tolerance. The effect of monthly FMD cycles on gene expression associated with mitochondrial metabolism and biogenesis in adipocytes and the sustained ketogenesis in HFCD-fed mice indicate a role for fat cell reprogramming in obesity prevention. These effects of an FMD on adiposity and cardiac ageing could explain the protection from HFCD-dependent early mortality.

17Morphogenesis in walled organisms represents a highly controlled process that 18 involves cell proliferation and expansion; cell growth is regulated through changes in 19 the structure and mechanics of the cells' walls. Despite taking different evolutionary 20 paths, land plants and some brown algae exhibit developmental and morphological 21 similarities; however, the role of the algal cell wall in morphogenesis remains heavily 22 similar to those observed in plants. In addition, our data show that cleavage-type cell 41 proliferation exists in brown algae similar to that seen in plant and animal systems 42 indicating a possible conserved developmental phenomenon across the branches of 43 multicellular life. 44 103 G sugars present: mixed MG regions are most flexible, followed by M-rich regions, 104 with G-rich regions being the stiffest (MG flexibility > MM > GG; (47)). 105 Since Fucus affords a maternally-free developing embryo, it is an ideal system 106 for studying the mechanics of morphogenesis in brown algae, and, specifically, that 107 underlying cell expansion. 108 Here, we explore the mechanical basis of wall-mediated growth in the Fucus 109 serratus embryo through a combination of atomic force microscopy and alginate 110 immunohistochemistry. Furthermore, we present the first brown algal embryo 111 6 development transcriptome and explore the expression of cell wall biosynthesis and 112 modification genes in early embryo growth. We utilize our data to hypothesize that cell 113 expansion in the Fucus zygote is regulated, in part, by alginate biochemistry and 114 resulting wall mechanics. Our findings point to a physical similarity between the 115 mechanical regulation of cell expansion in plants and brown algae. 116

Quantitative gene expression analysis is an important tool in the scientist’s belt. The identification of evenly expressed reference genes is necessary for accurate quantitative gene expression analysis, whether by traditional RT-PCR (reverse-transcription polymerase chain reaction) or by qRT-PCR (quantitative real-time PCR; qPCR). In the Stramenopiles (the major line of eukaryotes that includes brown algae) there is a noted lack of known reference genes for such studies, largely due to the absence of available molecular tools. Here we present a set of nine reference genes (Elongation Factor 1 alpha (EF1A), Elongation Factor 2 alpha (EF2A), Elongation Factor 1 beta (EF1B), 14-3-3 Protein, Ubiquitin Conjugating Enzyme (UBCE2), Glyceraldehyde-3-phosphate Dehydrogenase (GAPDH), Actin Related Protein Complex (ARP2/3), Ribosomal Protein (40s; S23), and Actin) for the brown alga Fucus distichus. These reference genes were tested on adult sporophytes across six abiotic stress conditions (desiccation, light and temperature modification, hormone addition, pollutant exposure, nutrient addition, and wounding). Suitability of these genes as reference genes was quantitatively evaluated across conditions using standard methods and the majority of the tested genes were evaluated favorably. However, we show that normalization genes should be chosen on a condition-by-condition basis. We provide a recommendation that at least two reference genes be used per experiment, a list of recommended pairs for the conditions tested here, and a procedure for identifying a suitable set for an experimenter’s unique design. With the recent expansion of interest in brown algal biology and accompanied molecular tools development, the variety of experimental conditions tested here makes this study a valuable resource for future work in basic biology and understanding stress responses in the brown algal lineage.

In plants and parenchymatous brown algae the body arises through the activity of an apical meristem (a niche of cells or a single cell). The meristem produces lateral organs in specific patterns, referred to as phyllotaxis. In plants, two different control mechanisms have been proposed: one is position-dependent and relies on morphogen accumulation at future organ sites; the other is a lineage-based system which links phyllotaxis to the apical cell division pattern. Here we examine the apical patterning of the brown alga, Sargassum muticum, which exhibits spiral phyllotaxis (137.5° angle) and an unlinked apical cell division pattern. The Sargassum apex presents characteristics of a self-organising system, similar to plant meristems. In contrast to complex plant meristems, we were unable to correlate the plant morphogen auxin with bud positioning in Sargassum, nor could we predict cell wall softening at new bud sites. Our data suggests that in Sargassum muticum there is no connection between phyllotaxis and the apical cell division pattern indicating a position-dependent patterning mechanism may be in place. The underlying mechanisms behind the phyllotactic patterning appear to be distinct from those seen in plants.