Macronuclear persistence of sequences normally eliminated during development in Tetrahymena thermophila

During conjugation in the ciliated protozoan, Tetrahymena thermophila , a somatic MAC-ronucleus develops from the germinal MICronucleus. Ten to 20 percent of the MIC genome is eliminated during this process. Three repetitive families have been identified which have different levels of repetition in the MIC and are eliminated to different degrees in the MAC. Some members of two of these families persist in the MAC. In this study, we have looked at these persistent sequences in the MAC of cell lines from a variety of sources including several inbed strains, two sets of caryonides, caryonidal subclones, and vegetatively aged cell clones. The results suggest that the sequences that remain in the MAC have a genetic predisposition to persist. However, epigenetic variations occur as the MAC develops so that only some of the persistent sequences are actually observed in a particular MAC. Polymorphisms may be generated if alternative processing of a single MIC segment occurs. These polymorphisms can later be resolved by phenotypic assortment during vegetative growth. These facultatively persistent sequences appear to differ from sequences previously described in this organism.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/50176/1/1020060205_ftp.pd

Alternative Processing of Sequences During Macronuclear Development in Tetrahymena thermophila 1

DNA is eliminated during development of the somatic MACronucleus from the germinal MICronucleus in the ciliated protozoan, Tetrahymena thermophila. Facultatively persistent sequences are a class of sequences that persist in the MAC DNA of some cell lines but are eliminated from the MAC DNA of other cell lines. One cloned MAC fragment contains a persistent sequence as well as sequences normally retained in the MAC. When this cloned fragment was used to construct MAC restriction maps of this region in cell lines whose MAC DNAs do, or do not, contain the persistent sequence, extensive variation in the map flanking this region was observed. The different DNA rearrangements of this MIC segment are epigenetically determined during or soon after MAC development. Moreover, different rearrangements may occur among the 45 copies of this MIC segment as a MAC is formed, resulting in polymorphisms that are later resolved by phenotypic assortment.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/74715/1/j.1550-7408.1986.tb05551.x.pd

Nutritive Levels in Plants from Stripmined Areas in Eastern Ohio

Author Institution: Ohio Cooperative Wildlife Research Unit, The Ohio State UniversityData on nutritive quality of vegetation for stripmined lands were obtained in 1972-73 from 2 Ohio counties, one having generally acidic spoil banks and the other having calcareous spoils. Proximate analysis of water, ash, crude protein, ether extract, cell-wall constituents, and nitrogen-free extract revealed few significant differences between plants growing on stripped and undisturbed (control) plots. Plants also were analyzed for 6 essential elements by emission spectrography. Levels of potassium were significantly higher in plants from control plots. Calcium levels were higher in plants from alkaline spoils, and manganese levels were higher in plants from acidic mined plots. Manganese levels exceeded 600 ppm in some plant samples from acidic spoil banks. Even when plants from stripped plots contained significantly less of a given element, levels were generally not low enough to indicate nutrient deficiency

Water Quality of the North End of Seneca Lake: 1991-2006

The Seneca County Soil and Water Conservation District (SCSWCD) has collected limnological data on the waters of the northern end of Seneca Lake since 1991. This report updates the 1999 report (Makarewicz et al. 1999) with data taken by the SCSWCD from 1999 to 2006. The purpose of monitoring the northern portion of Seneca Lake was to determine the health of the Seneca Lake ecosystem and to determine if any temporal trends existed in Seneca Lake water quality. The water quality of Seneca Lake has been studied since the early 1900s when secchi disk readings were first taken. At that time, the trophic state of Seneca Lake was classified as oligotrophic; that is, nutrient concentrations and primary production were low and transparency high. Water clarity remained approximately the same up through the early 1930s. By the late 1970s, water clarity generally decreased, indicating that the lake’s trophic status was mesotrophic. Total phosphorus concentrations from the 1970s were into the mesotrophic range. Chlorophyll-a concentration also illustrated the trend toward more productive waters in Seneca Lake in the early to mid 1970s. Similarly, in the early 1970s, the transparency of Seneca Lake had decreased to within the eutrophic range. These low transparency values were observed into the early 1990s. Based on the sampling done by the Seneca County Soil and Water Conservation District from 1991 through 2006, an improvement in water quality of Seneca Lake is suggested – at least at the north end where the samples were taken. The trophic status of Seneca Lake is currently best described as oligotrophic. In conclusion, water quality of Seneca Lake appears to have improved since the early 1970s. However, the increase in total phosphorus levels from 2003 to 2005 represents an increase of some concern as they represent the highest values in the last 14 years

Water Quality Monitoring on Cratsley Gully and Honeoye Inlet, Part of the Honeoye Lake Watershed

The presence of soluble, sedimentary rocks in the watershed of the Finger Lakes determines the chemical regimes comprising the lakes (Schaffner and Oglesby 1978). As the rest of the Finger Lakes, Honeoye Lake has an abundance of calcium and bicarbonate ions (Schaffner and Oglesby 1978). Nitrate + nitrite values for Honeoye Lake in 1993 (mean = 0.02 mg/L) were significantly lower (P\u3c0.02) than levels from 1973 (mean = 0.07 mg/L) (Crego 1994). In 1973, Honeoye Lake had the highest total phosphorus (TP) concentration of the eight Finger Lakes examined (21.7 μg/L, August) (Schaffner and Oglesby 1978). However, there were no significant differences in total phosphorus and soluble reactive phosphorus (SRP) concentrations from 1973 to 1993 (Crego 1984). During the summer, Honeoye Lake’s deepest waters are not completely oxygenated and 5 experience algal blooms that impair water quality (NYSDEC Region 8). Eelgrass, pondweed, Eurasian milfoil, and water stargrass are the predominant rooted aquatic plant species that are found in near shore areas out to a depth of approximately 15 feet (~5m) (NYSDEC Region 8). The large macrophyte community (weeds) and the reoccurring blooms of algae on the lake are in part the driving force of this study. Excess nutrients, especially phosphorus, can be a major cause of an over abundance of macrophytes and algae. One source of nutrients to a lake is losses from watershed. The goal of this study was to document the level of nutrient and soil loss from the watershed into Honeoye Lake

Segment Analysis Of Fish Creek The Location Of Sources Of Pollution

The Orleans County Soil and Water Conservation District has monitored the waterways of Orleans County since 1997 in collaboration with the State University of New York at Brockport\u27s Department of Environmental Science and Biology. Monitoring efforts have included the installation of a permanent gauging and sampling stations located on Johnson Creek, Sandy Creek and Oak Orchard Creek (1, 2). The District and SUNY Brockport have also completed a Stressed Stream Analyses on Johnson Creek in 2000 (3), Marsh Creek in 2001 (4) and Otter Creek in 2003 (5). SUNY Brockport has provided analytical services for water chemistry, data interpretation, as well as consulting services on the direction of the monitoring program. Fish Creek is located in the southern portion of the Lake Ontario watershed, Orleans County, New York, and flows into Oak Orchard Creek south of Route 104 and east of Bates Road in the Town of Ridgeway, New York (Fig. 1). The goal of this project was to identify the sources of nutrients, soils and salts within the Fish Creek watershed through a process called segment analysis (6). With this report, we provide evidence suggesting the location, identity of pollutants and the intensity of pollution sources in the Fish Creek watershed

Loss of Nutrients and Soil from Sandy Pond Tributaries, Oswego County, N.Y.

North and South Sandy Ponds comprise one of the largest coastal bay ecosystems on Lake Ontario. Unlike South Sandy Pond, North Sandy Pond supports intensive recreational activities and intensive shorefront residential development including a commercial campground and several marinas. Both ponds have an over abundance of nutrients and are the likely cause of the over abundance of aquatic weeds in the water. The limnological literature is quite clear on the causes of this unwanted overabundance of aquatic weeds and microscopic plants – an excess amount of nutrients or fertilizers are entering the water. A short list of possible sources of nutrients and soil include point and non-point sources in the watershed of Sandy Pond, septic system losses in direct drainage areas adjacent to the Pond (e.g., from cottages and boats), and resuspension of nutrients from sediments in the Pond itself. The purpose of this study was to determine the relative importance of losses of soil and nutrients from the five major tributaries draining sub-watersheds of North Sandy Pond hereafter referred to as Sandy Pond. Stream discharge and concentration of nitrate, total phosphorus, sodium, total suspended solids, and total Kjeldahl nitrogen were measured and converted into the amount of material lost from the watershed or loading into Sandy Pond during events and non-events

The Significance Of Phosphorus Released From The Sediment Under Anoxic Conditions In Sodus Bay, N.Y.

The goal of this study was to evaluate the loss of phosphorus from the sediment to the anoxic hypolimnion of Sodus Bay, New York. Total phosphorus (TP) and soluble reactive phosphorus (SRP) concentrations were monitored weekly throughout the water column in Sodus Bay from 16 May 2001 to 22 September 2001. Increased amounts of TP and SRP into the hypolimnion, during periods of hypolimnetic anoxia, indicated that phosphorus was being released from the sediment. On an annual basis, the sediments contributed 600 kg of phosphorus to Sodus Bay (24 kg/d x 25 days, from 8/18 to 9/12) in 2001. This is 7.5% of the annual input of phosphorus to Sodus Bay from the watershed (8,004 kg P, annual average from 1989 to 1994). If the period of anoxia in the hypolimnion is considered (25 days in the late summer), the amount of phosphorus released by the sediments into the hypolimnion is still 600 kg but the amount entering from the watershed is 123 kg of P. That is, phosphorus release into the hypolimnion is 488% greater than the amount entering from the watershed during this period of the year. Since the sediment is releasing phosphorus at a time when inputs from the watershed are minimal, phosphorus inputs from the sediments may prove to be a more important factor in the stimulation of late summer algal blooms than inputs from the watershed